Abstract The first example of luminescent monosubstituted polyacetylenes (mono‐PAs) is presented, based on a contracted cis‐cisoid polyene backbone. It has an excellent circularly polarized luminescence (CPL) performance with a high dissymmetric factor (up to the order of 10 −1 ). The luminescence stems from the helical cis‐cisoid PA backbone, which is tightly fixed by the strong intramolecular hydrogen bonds, thereby reversing the energy order of excited states and enabling an emissive energy dissipation. CPL switches are facilely achieved by the solvent and temperature through reversible conformational transition. By taking advantages of fast response and high sensitivity, the thin film of mono‐PAs could be used as a CPL‐based probe for quantitative detection of trifluoroacetic acid with a wider linear dynamic range than those of photoluminescence and circular dichroism. This work opens a new avenue to develop novel smart CPL materials through modulating conformational transition.
Abstract The chainmail catalyst by encapsulating an active species within the carbon support is a well‐established concept to endorse extraordinary stability for catalytic reactions under harsh conditions. Conventional chainmail catalysts inevitably suffer from poor accessibility to active sites, leading to extra voltage to compensate the sluggish diffusion kinetics in electrocatalysis. Herein, the naturally abundant wood material is converted into a monolithic chainmail electrocatalyst by encapsulating cobalt nanoparticles within N‐doped carbonized wood. Such a monolithic chainmail catalyst is employed directly as electrode for hydrogen evolution (HER), oxygen evolution (OER), and monosaccharide oxidation reactions (MOR) with benchmark performance. By coupling the HER with MOR, the electrolyzer equipped with the monolithic chainmail catalyst allows hydrogen production at a current density of 100 mA cm −2 with a full cell voltage of only 1.36 V. Such design of wood‐derived chainmail catalyst provides a promising way to fabricate robust electrocatalysts for future production of hydrogen and value‐added chemicals.
The concurrent targeting of Fms-like tyrosine kinase 3 (FLT3)/VEGFR2/Histone deacetylase (HDAC) represents a novel and promising therapeutic strategy for acute myeloid leukemia. In this work, we hybridized essential pharmacophores from sorafenib and SAHA (vorinostat) and then conducted structure–activity relationship studies to identify two lead compounds 26 and 32 that potently inhibit FLT3, VEGFR2, and HDAC in a nanomolar range. In cell evaluation, compounds 26 and 32 exhibited potent proliferative activities against a panel of leukemia cells including MV4-11 and MOLM-13. Western blotting analysis also showed that compounds 26 and 32 suppressed the phosphorylation of FLT3, STAT3, and ERK1/2 and increased histone H3 acetylation in a dose-dependent manner, indicating the effective inhibition of FLT3, VEGFR2, and HDAC. Supported by its pharmacokinetic properties, compound 26 showed remarkable anticancer efficacy in a MV4-11 xenograft model. Additionally, it demonstrated superior efficacy compared to midostaurin and gilteritinib in the Ba/F3-FLT3-ITD-N701K xenograft model.
Multiple and two-way reversible shape memory polymers (M/2W-SMPs) are highly promising for many fields due to large deformation, lightweight, strong recovery stress, and fast response rates. Herein, a semi-crystalline block poly(urethane-urea-amide) elastomers (PUUAs) are prepared by the copolymerization of isocyanate-terminated polyurethane (OPU) and amino-terminated oligomeric polyamide-1212 (OPA). PUUAs, composed of OPA as stationary phase and PTMEG as reversible phase, exhibit excellent rigidity, flexibility, and resilience, and cPUUA-C7 -S25 exhibits the best tensile property with strength of 10.3 MPa and elongation at break of 360.2%. Besides, all the PUUAs possess two crystallization/melting temperatures and a glass transition temperature, which endow PUUAs with multiple and reversible two-way shape memory effect (M/2W-SME). Physically crosslinked PUUA-C0 -S25 exhibits excellent dual and triple shape memory, and micro chemically crosslinked cPUUA-C7 -S25 further shows quadruple shape memory behavior. Additionally, both PUUA-C0 -S25 and cPUUA-C7 -S25 have 2W-SME. Intriguingly, cPUUA-C7 -S25 can achieve a higher temperature (up to 165 °C) SME, which makes it suitable for more complex and changeable applications. Based on the advantages of M/2W-SME, a temperature-responsive application scenario where PUUAs can transform spontaneously among different shapes is designed. These unique M/2W-SME and high-temperature SME will enable the applications of high-temperature sensors, actuators, and aerospace equipment.
Most existing group activity recognition methods construct spatial-temporal relations merely based on visual representation. Some methods introduce extra knowledge, such as action labels, to build semantic relations and use them to refine the visual presentation. However, the knowledge they explored just stay at the semantic-level, which is insufficient for pursing notable accuracy. In this paper, we propose to exploit knowledge concretization for the group activity recognition, and develop a novel Knowledge Augmented Relation Inference framework that can effectively use the concretized knowledge to improve the individual representations. Specifically, the framework consists of a Visual Representation Module to extract individual appearance features, a Knowledge Augmented Semantic Relation Module explore semantic representations of individual actions, and a Knowledge-Semantic-Visual Interaction Module aims to integrate visual and semantic information by the knowledge. Benefiting from these modules, the proposed framework can utilize knowledge to enhance the relation inference process and the individual representations, thus improving the performance of group activity recognition. Experimental results on two public datasets show that the proposed framework achieves competitive performance compared with state-of-the-art methods.
Download This Paper Open PDF in Browser Add Paper to My Library Share: Permalink Using these links will ensure access to this page indefinitely Copy URL Copy DOI
P-doping extended the absorption wavelength of carbon dots (CDs) from the UV-Vis to the NIR region. P-CD-catalyzed NIR-ATRP resulted in a well-controlled polymerization process, as well as temporal control and chain fidelity.
The effects of rare earth elements lanthanum on growth and antioxidation system of the greengrocery under salt stress were investigated. The seed of greengrocery were cultureed in Hoagland nutrient solution with 50mg·L -1 NaCl and 20, 40, 60, 80, 100, 150mg·L -1 Lanthanum. Then the treatments cultured in Hoagland nutrient solution with 50mg·L -1 NaCl, 20mg·L -1 lanthanum as control. After continued for two weeks, seed germination rate and super oxide dismutase(SOD) and peroxidase ( POD) activities, malondialdehyde (MDA) were measured. The results showed that salt stress could inhibite seed germination and seedling growth of greengrocery, fresh weight marked reduced, dwarf seedlings. Low concentration LaCl 3 (20~80mg·L -1 )could promote seed germination and seedling growth of greengrocery, fresh weight marked increased, high seedlings. Salt stress significantly reduced the chlorophyll content of and adding suitable concentration LaCl 3 (20~100mg·L -1 )could improve of chlorophyll content of the greengrocery seedlings under salt stress and enhance its light transformation ability. But under hoagland nutrient solution with 20mg·L -1 LaCl 3 processing, chlorophyll content of the greengrocery seedlings had marked reduced(P<;0.05 ). Salt stress can induce the generation of protein. The treaments with proper density LaCl 3 (40~80mg·L -1 ) were able to alleviate the pressure of salt stress, and improve the soluble protein content of greengrocery seedling. High concentration LaCl 3 (100~150mg·L -1 ) under salt stress marked inhibited the the soluble. protein produce of greengrocery seedling. Salt stress could stimulate greengrocery seedlings induction their antioxidant enzymes protection system, make antioxidant enzymes of greengrocery seedling increase, MDA content reduced, Suitable concentration LaCl 3 (40-80mg·L -1 ) under salt stress can promote antioxidant enzymes relieve the damage of salt stress on seedling, then MDA content reduced. but high levels of LaCl 3 (100~150mg·L -1 )is likely to produce poisonous effect on cells leaded to antioxidant enzymes activity abate, MDA content increased. In brief, salt stress(50mg·L -1 ) could inhibited seed germination and seedling growth of greengrocery, and induction antioxidant enzymes emerge, MDA content increased. The treatment with optimum concentration of LaCl 3 could significantly increase antioxidant enzyme activities of greengrocery seedlings, enhance its scavenging reactive oxygen species, reduce lipid per oxidation under salt stress, in order to effectively alleviate the salt stress injury and increase their salt tolerance, and promote greengrocery seedling growth, The optium concentration was 40~80mg·L -1 .
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)
'/%3e%3c/defs%3e%3cpath fill='%23012169' d='M0 0h10080v5040H0z'/%3e%3cpath stroke='%23fff' stroke-width='.6' d='m0 0 6 3m0-3L0 3' clip-path='url(%23b)' transform='scale(840)'/%3e%3cpath stroke='%23e4002b' stroke-width='.4' d='m0 0 6 3m0-3L0 3' clip-path='url(%23c)' transform='scale(840)'/%3e%3cpath stroke='%23fff' stroke-width='840' d='M2520 0v2520M0 1260h5040'/%3e%3cpath stroke='%23e4002b' stroke-width='504' d='M2520 0v2520M0 1260h5040'/%3e%3cg fill='%23fff'%3e%3cuse xlink:href='%23d' x='2520' y='3780'/%3e%3cuse xlink:href='%23a' x='7560' y='4200'/%3e%3cuse xlink:href='%23a' x='6300' y='2205'/%3e%3cuse xlink:href='%23a' x='7560' y='840'/%3e%3cuse xlink:href='%23a' x='8680' y='1869'/%3e%3cuse xlink:href='%23e' x='8064' y='2730'/%3e%3c/g%3e%3c/svg%3e)