All‐polymer solar cells (all‐PSCs) have received attention in recent years for their desirable properties in power conversion efficiency and long‐term operational stability. However, it is still a ...big challenge to acquire an “ideal” vertical‐phase distribution of polymer/polymer blends due to the non‐ideal molecular conformations and mixing behaviors. Herein, a ternary‐assisted sequential solution deposition (SSD) strategy is adopted to regulate the vertical compositional profile of all‐PSCs. A favorable acceptor(donor)‐enriched phase near the cathode(anode) can be obtained by a ternary‐assisted SSD strategy. With such a compositional profile, the exciton yield and carrier density can be enhanced by the vertical component gradient. Remarkably, the non‐geminate recombination is suppressed with an improved exciton diffusion length (15.36 nm) that delivers an outstanding power conversion efficiency over 16% of the ternary PM6/PY‐IT:PDI‐2T SSD devices. This work demonstrates the success of ternary‐assisted SSD strategy in reorganizing the vertical‐phase distribution, which provides a feasible route for a potential ternary device construction toward efficient all‐polymer photovoltaics.
A vertical compositional gradient within the active layer with a donor‐enriched active‐anode interface and an acceptor‐enriched active‐cathode interface can be achieved by sequential solution deposition treatment in PM6/PY‐IT:PDI‐2T device. As a result, charge transfer properties and exciton diffusion length are promoted with suppressed non‐geminate recombination to deliver an outstanding power conversion efficiency of 16% in the all‐polymer solar cells, which are verified with transient absorption, time‐resolved photoluminescence, and capacitance‐voltage measurements.
Ischemic cerebrovascular disease (ICVD) is a major cause of mortality and disability worldwide and is often caused by atherosclerosis. As a systemic disease, atherosclerosis usually affects multiple ...vascular beds, mainly including cerebral, coronary, and peripheral arteries. Therefore, ICVD is easily complicated by lower-extremity peripheral arterial disease (PAD). ICVD patients with PAD have more serious symptoms and a worse prognosis, however, neurologists might neglect the evaluation and management of the coexistent PAD, and there is still a lack of consensuses about the diagnosis and treatment for such patients. By summarizing relevant research progresses, this review showed that duplex ultrasound had more advantages in the early screening and evaluation of PAD in ICVD patients among multiple methods to diagnose PAD. Furthermore, the current evidence seems to support that single-drug antiplatelet can be used as the basic treatment, and new antithrombotic strategies, such as ticagrelor only or aspirin combined with low-dose rivaroxaban are expected to further reduce the incidence of stroke for ICVD patients with PAD. More effective treatments would be explored by large-scale trials to guide the clinical management to prevent secondary stroke for such patients.
Molecular dynamics simulations have revealed the collapse mechanism of a void in cubic metals under shock compression along 100 direction. The results show that the void collapse is caused by ...emitting dislocations from its surface. The type of cubic metal plays a decisive role in the subsequent microstructural evolution around the void. Void in face-centered-cubic metals collapses by emitting Shockley dislocations from its surface when piston velocity exceeds the threshold; while void in body-centered-cubic metals collapses by emitting prismatic dislocation loops, which are formed by the reaction of edge dislocations. Simulation results also reveal that the type of dislocation that induces void collapse is independent of void size. Finally, based on the elastic theory, we find that the maximum resolved shear stress along the slip direction determines the types of dislocation emitted from the voids.
The combination of transition‐metal catalysis and organocatalysis increasingly offers chemists opportunities to realize diverse unprecedented chemical transformations. By combining iridium with ...chiral thiourea catalysis, direct enantioselective reductive cyanation and phosphonylation of secondary amides have been accomplished for the first time for the synthesis of enantioenriched chiral α‐aminonitriles and α‐aminophosphonates. The protocol is highly efficient and enantioselective, providing a novel route to the synthesis of optically active α‐functionalized amines from the simple, readily available feedstocks. In addition, the reactions are scalable and the thiourea catalyst can be recycled and reused.
The first enantioselective reductive cyanation and phosphonylation of secondary amides have been achieved by the combination of iridium with chiral thiourea catalysis. The protocol is highly efficient and enantioselective, providing a novel route for the synthesis of optically active α‐aminonitriles and α‐aminophosphonates from bench‐stable feedstocks.
In this work, the 3D four petaled flower-like, cube-like and rod-like m-BiVO4 samples and four corners star-like m-BiVO4/BiOBr heterojunctions with various exposed (040) facets were successfully ...prepared by a hydrothermal method. The microstructure and the crystalline structure of as-prepared m-BiVO4 and m-BiVO4/BiOBr heterojunctions influenced by molar ratio of Br:V had been investigated by XRD, SEM, TEM, HRTEM, N2 absorption–desorption, XPS, PL and DRS. In addition, the photocatalytic performance of the prepared m-BiVO4 and m-BiVO4/BiOBr heterojunctions were evaluated by monitoring the degradation of Rhodamine B (RhB) contained wastewater under visible light irradiation. The highest photocatalytic degradation efficiency can be achieved for the m-BiVO4/BiOBr heterojunctions with Br:V molar ratio of 3:1, which was attributed to the predominately exposed (040) facets of m-BiVO4 and high exposing proportion of (001) facets of BiOBr, the highest BET, the lowest Eg and the worst recombination rate of photo-generated electron-hole pairs.
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•BiVO4 and BiVO4/BiOBr with various facets and morphologies were prepared.•Effect of Br:V molar ratios on as-prepared samples was studied.•The highest removal efficiency of RhB was obtained over the sample with Br:V = 3:1.
This work investigated the influence of melamine up to 15 wt% on the stimulation response properties of organic silicone polymer elastomer. The opacity of organic silicone film was attributed to the ...addition of melamine. For silicone and melamine composite thin films, deformation was increased from 152 to 172%, because the density of NH···O type hydrogen bond decreased the thermal motion of the polymer chain. The thin film of fluorescence and phosphorescence spectra indicated that the maximum luminescence wavelength red‐shifted about 14 nm. The Elastomer with melamine exhibited two‐dimensional stimulus response performance with the change of scale shape‐time‐afterglow emission properties. The phosphorescence of the silicone composite film was derived from the energy donor of melamine. In summary, the study provides detailed guidelines for the preparation of multi‐dimensional organic room temperature phosphorescent elastic materials.
Coordination-directed self-assembly has become a well-established technique for the construction of functional supramolecular structures. In contrast to the most often exploited transition metals, ...trivalent lanthanides LnIII have been less utilized in the design of polynuclear self-assembled structures despite the wealth of stimulating applications of these elements. In particular, stereochemical control in the assembly of lanthanide chiral cage compounds is not easy to achieve in view of the usually large lability of the LnIII ions. We report here the first examples of stereoselective self-assembly of chiral luminescent europium coordination tetrahedral cages and their intriguing self-sorting behavior. Two pairs of R and S ligands are designed on the basis of the pyridine-2,6-dicarboxamide coordination unit, bis(tridentate) L1 and tris(tridentate) L2. Corresponding chiral Eu4(L1)6 and Eu4(L2)4 topological tetrahedral cages are independently assembled via edge- and face-capping design strategies, respectively. The chirality of the ligand is transferred during the self-assembly process to give either Δ or Λ metal stereochemistry. The self-assembled cages are characterized by NMR, high-resolution ESI-TOF-MS, and in one case by X-ray crystallography. Strict control of stereoselectivity is confirmed by CD spectroscopy and NMR enantiomeric differentiation experiments. Narcissistic self-sorting is observed in the self-assembly process when two differently shaped ligands L1 and L2 are mixed. More impressively, distinct self-sorting behavior between Eu4(L1)6 and Eu4(L2)4 coordination cages is observed for the first time when racemic mixtures of ligands are used. We envisage that chiral luminescent lanthanide tetrahedral cages could be used in chiroptical probes\sensors and enantioselective catalysis.
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The effect of a 1/2111 screw dislocation on the growth of helium bubble in tungsten is investigated by molecular dynamics simulation method. When helium bubble grows at sites less ...than 3 nm away from the dislocation, tungsten self-interstitial atoms (SIAs) pushed out by the growing bubble are absorbed by and then migrate rapidly along the dislocation line, inducing the screw dislocation to evolve into a helical configuration. The existence of screw dislocation can facilitate the growth of helium bubble. The interaction energies between the screw dislocation and point defects (helium, SIA and vacancy) are calculated. The interaction energies are all negative, indicating that the screw dislocation can attract and serve as a sink for these point defects. Further investigation shows that the interactions between the screw dislocation and these point defects are local, and stem from the special stress distribution pattern of the screw dislocation.
To investigate the distribution and variability of trace metal pollution in the Chinese coastal waters, over 1000 adult oyster individuals were collected from 31 sites along the entire coastline, ...spanning from temperate to tropical regions (Bohai Sea, Yellow Sea, East China Sea and South China Sea), between August and September 2015. Concentrations of macroelements sodium (Na), potassium (K), calcium (Ca), magnesium (Mg) and phosphorus (P) and trace elements cadmium (Cd), copper (Cu), zinc (Zn), nickel (Ni), lead (Pb), chromium (Cr), silver (Ag), and titanium (Ti) in these oysters were concurrently measured and analyzed. The results showed high Ti, Zn and Cu bioaccumulation in oysters from Guangdong (South China Sea) and Zhejiang (East China Sea). Oysters at Nanji Island (Wenzhou) and Daya Bay (Huizhou) accumulated significantly high concentrations of Ni and Cr. The elements in these oysters were several times higher than the national food safety limits of China. On the other hand, the present study found that normalization of metals by salinity (Na) and nutrient (P) could reflect more details of metal pollution in the oysters. Biomonitoring of metal pollution could benefit from incorporating the macroelement calibration instead of focusing only on the total metal concentrations. Overall, simultaneous measurement of macroelements and trace metals coupled with non-linear analysis provide a new perspective for revealing the underlying mechanism of trace metal bioavailability and bioaccumulation in marine organisms.
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•High Ti, Zn & Cu in oysters of Southern China due to intensive industrial activity.•Hot spots of Cr and Ni were higher than the food safety limits in a few locations.•Na & P normalization of metals in oysters reflect more details of metal pollution.•Macroelement calibration benefits biomonitoring instead of metal concentrations.
Simultaneous measurements of macroelements and trace metals coupled with non-linear analysis provide important information for interpreting the biomonitoring data.
Background and Purpose
Cancer cells exhibit more dependence on iron and enhanced sensitivity to iron‐dependent, programmed cell death (ferroptosis) than normal cells. Quercetin exerts anti‐cancer ...effects, but the underlying molecular mechanism is largely unknown. In this study, we aimed to investigate the involvement of lysosome function and ferroptosis in the anti‐cancer potential of quercetin.
Experimental Approach
We used MTT assays and DNA content analysis to evaluate the cytotoxicity, colony formation assay to investigate cell proliferation, and flow cytometry and confocal microscopy to detect lysosomal acidification and protease enzyme activity. Western blotting, cell subfractionation, RT‐PCR and siRNA transfection were used to establish molecular mechanisms of action.
Key Results
Quercetin is known to promote p53‐independent cell death in various cancer cell lines. Although quercetin induces autophagy, genetic silencing of Atg7 fails to affect quercetin‐induced cell death. In contrast, both lysosome inhibitors and knockdown of the transcription factor EB can prevent quercetin‐induced cell death, suggesting the involvement of lysosome. Next, quercetin is found to induce lysosomal activation sequentially through nuclear translocation of EB and transcriptional activation of lysosomal genes. Notably, quercetin promoted lysosome‐dependent ferritin degradation and free iron release. This action and quercetin‐induced ROS generation synergistically resulted in lipid peroxidation and ferroptosis. Furthermore, Bid may link ferroptosis with apoptosis to cause cell death.
Conclusion and Implications
Quercetin induced EB‐mediated lysosome activation and increased ferritin degradation leading to ferroptosis and Bid‐involved apoptosis. Results from this study may expand our current knowledge about the mechanism of quercetin as an anti‐cancer agent.
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