Quasi-two-dimensional (quasi-2D) Ruddlesden-Popper (RP) perovskites such as BA
Cs
Pb
Br
(BA = butylammonium, n > 1) are promising emitters, but their electroluminescence performance is limited by a ...severe non-radiative recombination during the energy transfer process. Here, we make use of methanesulfonate (MeS) that can interact with the spacer BA cations via strong hydrogen bonding interaction to reconstruct the quasi-2D perovskite structure, which increases the energy acceptor-to-donor ratio and enhances the energy transfer in perovskite films, thus improving the light emission efficiency. MeS additives also lower the defect density in RP perovskites, which is due to the elimination of uncoordinated Pb
by the electron-rich Lewis base MeS and the weakened adsorbate blocking effect. As a result, green light-emitting diodes fabricated using these quasi-2D RP perovskite films reach current efficiency of 63 cd A
and 20.5% external quantum efficiency, which are the best reported performance for devices based on quasi-2D perovskites so far.
Core/shell structured metal halide perovskite nanocrystals (NCs) are emerging as a type of material with remarkable optical and electronic properties. Research into this field has been developing and ...expanding rapidly in recent years, with significant advances in the studies of the shell growth mechanism and in understanding of properties of these materials. Significant enhancement of both the stability and the optical performance of core/shell perovskite NCs are of particular importance for their applications in optoelectronic technologies. In this review, the recent advances in core/shell structured perovskite NCs are summarized. The band structures and configurations of core/shell perovskite NCs are elaborated, the shell classification and shell engineering approaches, such as perovskites and their derivative shells, semiconductor shell, oxide shell, polymer shell, etc. are reviewed, and the shell growth mechanisms are discussed. The prospective of these NCs in lighting and displays, solar cells, photodetectors, and other devices is discussed in the light of current knowledge, remaining challenges, and future opportunities.
Core/shell metal halide perovskite nanocrystals show enhanced stability and optical properties, which are beneficial for their applications in lighting and displays, solar cells, photodetectors, lasing, photocatalysis, and biomedical imaging. In this review, recent advances in synthetic strategies and shell growth of core/shell nanocrystals are reviewed, and their enhanced material properties and emerging applications are discussed.
It has been well-established that the deubiquitinating enzyme ubiquitin-specific peptidase 7 (USP7) supports cancer growth by up-regulating multiple cellular pathways, including Wnt/β-catenin ...signaling. Therefore, considerable efforts are directed at identifying and developing USP7 inhibitors. Here, we report that sesquiterpene lactone parthenolide (PTL) inhibits USP7 activity, assessed with deubiquitinating enzyme activity assays, including fluorogenic Ub-AMC/Ub-Rho110, Ub-VME/PA labeling, and Di-Ub hydrolysis assays. Further investigations using cellular thermal shift (CETSA), surface plasmon resonance (SPR), and mass spectrum (MS) assays revealed that PTL directly interacts with USP7. Consistent with the role of USP7 in stimulating Wnt signaling and carcinogenesis, PTL treatment inhibited the activity of Wnt signaling partly by destabilizing β-catenin. Moreover, using cell viability assays, we found that PTL suppresses the proliferation of colorectal cancer cells and induces apoptosis in these cells. Additionally, we examined the effects of two other sesquiterpene lactones (costunolide and α-santonin) on USP7 and Wnt signaling and found that α-methylene-γ-butyrolactone may provide a scaffold for future USP7 inhibitors. In summary, our findings reveal that PTL inhibits USP7 activity, identifying a potential mechanism by which PTL suppresses Wnt/β-catenin signaling. We further suggest that sesquiterpene lactones might represent a suitable scaffold for developing USP7 inhibitors and indicate that PTL holds promise as an anticancer agent targeting aberrant USP7/Wnt signaling.
Oceanic eddies play an important role in global energy and material transport, and contribute greatly to nutrient and phytoplankton distribution. Deep learning is employed to identify oceanic eddies ...from sea surface height anomalies data. In order to adapt to segmentation problems for multi-scale oceanic eddies, the pyramid scene parsing network (PSPNet), which is able to satisfy the fusion of semantics and details, is applied as the core algorithm in the eddy detection methods. The results of eddies identified from this artificial intelligence (AI) method are well compared with those from a traditional vector geometry-based (VG) method. More oceanic eddies are detected by the AI algorithm than the VG method, especially for small-scale eddies. Therefore, the present study demonstrates that the AI algorithm is applicable of oceanic eddy detection. It is one of the first few of efforts to bridge AI techniques and oceanography research.
Cancer has always been one of the most common malignant diseases in the world. Therefore, there is an urgent need to find potent agents with selective antitumor activity against cancer cells. It has ...been reported that antimicrobial peptides (AMPs) can selectively target tumor cells. In this study, we focused on the anti-tumor activity and mechanism of Brevinin-1RL1, a cationic α-helical AMP isolated from frog
skin secretions. We found that Brevinin-1RL1 preferentially inhibits tumor cells rather than non-tumor cells with slight hemolytic activity. Cell viability assay demonstrated the intermolecular disulfide bridge contributes to the inhibitory activity of the peptide as the antitumor activity was abolished when the disulfide bridge reduced. Further mechanism studies revealed that both necrosis and apoptosis are involved in Brevinin-1RL1 mediated tumor cells death. Moreover, Brevinin-1RL1 induced extrinsic and mitochondria intrinsic apoptosis is caspases dependent, as the pan-caspase inhibitor z-VAD-FMK rescued Brevinin-1RL1 induced tumor cell proliferative inhibition. Immunohistology staining showed Brevinin-1RL1 mainly aggregated on the surface of the tumor cells. These results together suggested that Brevinin-1RL1 preferentially converges on the cancer cells to trigger necrosis and caspase-dependent apoptosis and Brevinin-1RL1 could be considered as a pharmacological candidate for further development as anti-cancer agent.
Aims
Alcohol consumption could lead to a series of health problems and social issues. In the current study, we investigated the resting-state functional brain networks of healthy volunteers before ...and after drinking through graph-theory analysis, aiming to ascertain the effects of acute alcohol intake on topology and information processing mode of the functional brain networks.
Materials and methods
Thirty-three healthy volunteers were enrolled in this experiment. Each volunteer accepted alcohol breathalyzer tests followed by resting-state magnetic resonance imaging at three time points: before drinking, 0.5 h after drinking, and 1 h after drinking. The data obtained were grouped based on scanning time into control group, 0.5-h group and 1-h group, and post-drinking data were regrouped according to breath alcohol concentration (BrAC) into relative low BrAC group (A group; 0.5-h data,
n
= 17; 1-h data,
n
= 16) and relative high BrAC group (B group; 0.5-h data,
n
= 16; 1-h data,
n
= 17). The graph-theory approach was adopted to construct whole-brain functional networks and identify the differences of network topological properties among all the groups.
Results
The network topology of most groups was altered after drinking, with the B group presenting the most alterations. For global network measures, B group exhibited increased global efficiency, Synchronization, and decreased local efficiency, clustering coefficient, normalized clustering coefficient, characteristic path length, normalized characteristic path length, as compared to control group. Regarding nodal network measures, nodal clustering coefficient and nodal local efficiency of some nodes were lower in B group than control group. These changes suggested that the network integration ability and synchrony improved, while the segregation ability diminished.
Conclusion
This study revealed the effects of acute alcohol intake on the topology and information processing mode of resting-state functional brain networks, providing new perceptions and insights into the effects of alcohol on the brain.
Depression in bipolar disorder (BD) is often misdiagnosed as unipolar depression (UD), leading to mistreatments and poor clinical outcomes in many bipolar patients. Herein, we report direct ...comparisons between medication-free patients with BD and those with UD in terms of the microstructure and neurometabolites in eight brain regions.
A total of 20 patients with BD, 30 with UD patients, and 20 matched healthy controls (HCs) underwent 3.0T magnetic resonance imaging with chemical exchange saturation transfer (CEST) for glutamate (Glu; GluCEST) imaging, multivoxel magnetic resonance spectroscopy, and diffusion kurtosis imaging.
Compared with HCs, patients with UD showed significantly lower levels of multiple metabolites, GluCEST% values, and diffusional kurtosis mean kurtosis (MK) values in most brain regions. In contrast, patients with BD presented significantly higher levels of Glu in their bilateral ventral prefrontal white matter (VPFWM), higher choline (Cho)-containing compounds in their left VPFWM and anterior cingulate cortex (ACC), and higher GluCEST% values in their bilateral VPFWM and ACC; moreover, reduced MK in these patients was more prominent in the left VPFWM and left thalamus.
The findings demonstrated that both patients with UD and BD have abnormal microstructure and metabolic alterations, and the changes are not completely consistent in the prefrontal lobe region. Elevated Glu, Cho, and GluCEST% in the ACC and VPFWM of patients with UD and BD may help in differentiating between these two disorders. Our findings support the significance for the microstructural integrity and brain metabolic changes of the prefrontal lobe region in BD and UD.
Phosphoinositide 3-kinase (PI3Ks) are lipid kinases widely involved in cell proliferation, metastasis and differentiation. Constitutive activation of the PI3K/Akt/mTOR signaling are well confirmed in ...colorectal cancers (CRCs). In this study, we identified isopropyl 9-ethyl-1-(naphthalen-1-yl)-9 H-pyrido3,4-b indole-3-carboxylate (Z86), as a novel PI3Kα inhibitor with the IC
50
value of 4.28 µM. The binding of Z86 to PI3Kα was further confirmed with DARTS and CETSA assay. Immunofluorescence analysis and western blotting data demonstrated that Z86 effectively attenuated PI3K/AKT pathway. Z86 caused dramatic proliferation inhibition of CRCs through G0/G1 cycle arrest rather than apoptosis induction. Besides, the migration of CRCs was also relieved by Z86. The present study not only identified Z86 as a novel PI3Kα inhibitor with potent inhibitory efficiency on PI3K-mediated CRCs growth and migration, but also elucidated a reasonable molecular mechanism of Z86 in the Wnt signaling pathway inhibition.
Graphical Abstract
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