Circularly polarized light (CPL) detection is required in various fields such as drug screening, security surveillance and quantum optics. Conventionally, CPL photodetector needs the installation of ...optical elements, imposing difficulties for integrated and flexible devices. The established CPL detectors without optical elements rely on chiral organic semiconductor and metal metamaterials, but they suffer from extremely low responsivity. Organic-inorganic hybrid materials combine CPL-sensitive absorption induced by chiral organics and efficient charge transport of inorganic frameworks, providing an option for direct CPL detection. Here we report the CPL detector using chiral organic-inorganic hybrid perovskites, and obtain a device with responsivity of 797 mA W
, detectivity of 7.1 × 10
Jones, 3-dB frequency of 150 Hz and one-month stability, a competitive combined feature for circularly polarized light detection. Thanks to the solution processing, we further demonstrate flexible devices on polyethylene terephthalate substrate with comparable performance.
Metal halide perovskite quantum dots (QDs) recently have attracted great research attentions. However, blue-emitting perovskite QDs generally suffer from low photoluminescence quantum yield (PLQY) ...because of easily formed defects and insufficient surface passivation. Replacement of lead with low toxicity elements is also preferred toward potential commercial applications. Here, we apply Cl-passivation to boost the PLQY of MA3Bi2Br9 QDs to 54.1% at the wavelength of 422 nm, a new PLQY record for blue emissive, lead-free perovskite QDs. Because of the incompatible crystal structures between MA3Bi2Br9 and MA3Bi2Cl9 and the careful kinetic control during the synthesis, Cl– anions are engineered to mainly locate on the surface of QDs acting as passivating ligands, which effectively suppress surface defects and enhance the PLQY. Our results highlight the potential of MA3Bi2Br9 QDs for applications of phosphors, scintillators, and light-emitting diodes.
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IJS, KILJ, NUK, PNG, UL, UM
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In this work, the effects of three Citrus flavonoids (naringin, neohesperidin and hesperidin) on α‐amylase catalysed starch digestion were investigated. An inhibitory kinetics experiment ...demonstrated that they noncompetitively inhibit the activity of α‐amylase with Ki values of, respectively, 25.21 μm, 40.26 μm, 40.69 μm. Surface plasmon resonance assay showed three Citrus flavonoids can bind with starch with KD values of, respectively, 3.98 ± 0.20 mm, 4.92 ± 0.15 mm and 5.07 ± 0.17 mm. Scanning electron microscopy indicated they can delay the retrogradation of starch. The results of 1, 1‐diphenyl‐2‐picryl hydrazyl radical assay indicate that the antioxidant activities of three Citrus flavonoids are significantly decreased by interacting with starch. These results illustrated three Citrus flavonoids that retard the digestion of starch not only through interaction with α‐amylase, but also through interaction with starch.
The effects of three Citrus flavonoids on α‐amylase catalyzed starch digestion were investigated. Three Citrus flavonoids may not be inhibitors of α‐amylase with non‐competitive type, but could bind with starch.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
West Island is the second largest island in the Hainan Province, China and its surrounding sea area has a well-preserved coral reef ecosystem and high species diversity of coral reef fishes. ...Undoubtedly, coral reef fishes and coral reefs have complex symbiotic relationships and fish species diversity should reflect the healthy status of coral reef ecosystems. Environmental DNA (eDNA) is a useful and sensitive tool to detect fish species and causes less environmental damage than traditional fish survey methods. This paper investigated coral reef fish species of West Island, Hainan Province, China, based on eDNA and provided scientific data for understanding and protection of the coral reef ecosystem of the South China Sea.
The sea area surrounding West Island is the most important component of the coral reef ecosystem in the northern part of the South China Sea, which is also an essential part of the largest National Coral Reef Reserve in China. However, complete data of fish species distributed in this region have been a long-term gap. This study provides information on 41 fish species belonging to 28 genera, 16 families and three orders in this sea area and is the first complete record of coral reef fishes surrounding the West Island. In addition, the information of Molecular Operational Taxonomic Units (MOTUs) for taxon identification were also provided and it could contribute to building specific eDNA taxonomy database of coral reef fishes of the South China Sea. The study includes three datasets, with aspects of fish taxon-occurrences, MOTUs sequences and information of environmental indicators surrounding West Island, Hainan Province, China. The "fish taxon occurrences" dataset presents records involving taxonomic, distribution, habitat condition, latitude and longitude of 41 coral reef fish species detected, based on eDNA, the "MOTUs sequences" dataset provides MOTUs sequences and their abundance of 31 species detected and the "information of environmental indicators" dataset presents records of transparency, temperature, water pressure, dissolved oxygen, electrical conductivity, hydrogen and redox potential measured from five sampling localities.
Carbon nano peapods, with their electronic properties and spintronics, have attracted great attention regarding their potential applications when combined with fullerenes or their derivatives ...encapsulated inside. Herein, we have designed and synthesized a series of fullerene derivatives with different functional groups, which are then encapsulated into single-walled carbon nanotubes (SWCNTs). Accurate morphological characterization with high-resolution TEM reveals a clear correlation between the filling ratio of the peapods and the steric bulk of the functionalized groups. Further spectroscopic characterizations reveal diameter-selective interactions between the fullerene derivatives and SWCNTs, which, in turn, influence the electronic structures of the nanotubes. Our results have shed new light on the controlled synthesis and property-tuning of nano peapods.
Environmental DNA (eDNA) has been used in research relevant to fish ecology such as species diversity and conservation studies, threatened and invasive species monitoring, and analyses of population ...structure and distribution. How to choose the optimal laboratory protocols on the basis of the research targets is the first question to be considered when conducting an eDNA study. In this review, we searched 554 published articles using the topic subject ((eDNA or environmental DNA) and (fish)) within the time span 2011–2021 via Thompson Reuters Web of Science (WoS) and China National Knowledge Infrastructure (CNKI) literature databases, and screened 371 articles related to eDNA research on fish ecology. These articles were categorized into “article (334)”, “review (36)”, and “letter (1)” based on the type, and “article” was divided into “article (method research)” and “article (eDNA application)” in line with the study objectives. The experimental methods adopted in each study were reviewed, and advantages and disadvantages of the main protocols were analyzed for each step. We recommend a set of optimal protocols for regular eDNA-based fish diversity detection and present the following suggestions for water sample collection and subsequent sample processing and experiments. Sample size is suggested to be 2 L regardless of the type of water bodies; three water replicates are recommended per sampling site, and water collection sites should be designed to cover various water layers and micro-habitats within research areas. Filtration is the best method for collecting eDNA from the larger water samples; 0.45 μm glass fiber/glass microfiber (GF) filters and mixed cellulose acetate and nitrate (MCE) filters are recommended for use, and MCE filters are suitable for use in turbid waters; pre-filtration (>10 μm filtering membranes) can be used to prevent clogging. Freezing temperature storage can slow eDNA degradation, and this is the optimal way to store DNA no matter what filtering method is applied. The Qiagen DNeasy Blood and Tissue DNA extraction kit was the most economical and efficient DNA extraction method compared to other commercial kits. The 12S rRNA gene is the first choice for detecting interspecies variation in fishes, and five 12s primer sets, Ac12S, MDB07, Mi-Fish, Vert-12SV5, and Teleo, are recommended. The TruSeq DNA PCR-free LT Sample Prep kit and NEBNext DNA Library Prep Master Mix Set for the 454 kit can be chosen. The Illumina HiSeq platform can obtain sufficient data depth for fish species detection. QIIME and OBITools are independent software packages used for eDNA sequences analysis of fishes, and bioinformatic analyses include several indispensable steps such as filtering raw reads, clustering filtered reads into molecular operational taxonomic units (MOTUs) or amplicon sequence variants (ASVs), and completing taxon annotation. Contamination, inhibition, lack of reference DNA data, and bioinformatic analysis are key challenges in future eDNA research, and we should develop effective experimental techniques and analysis software regarding these aspects. This review intends to help eDNA beginners to quickly understand laboratory protocols applied in fish ecological research; the information will be useful for the improvement and development of eDNA techniques in the future.
Four 2-hydroxy-
-alkyl-
-phenyl-nicotinamides (
-
) were synthesized, and their crystal structures were analyzed to investigate the effect of substitution on their crystal packing of
...-phenyl-2-hydroxynicotinanilides. In these compounds, substituents were introduced on the amide N, leading to a peptoid-like structure. One solvent-free form and two hydrates were harvested for compound
, and one anhydrous form and one hydrate were obtained for compound
. Polymorphism was observed in compounds
and
. The molecules were found to be in the keto form rather than the enol tautomer. Because of steric effects, the molecules took on an
configuration, leading to a hairpin-like geometry. A lactam-lactam dimer synthon was formed in all solvent-free structures, and a tetramer motif was observed for the first time. Dehydration of the two hydrates of
and the hydrate of
led to their respective solvent-free form. Phase transition between the polymorphs was revealed in compound
. Theoretical calculations, including conformational energy evaluation, hydrate forming propensity assessment, and lattice energy appraisal, were performed to provide a reasonable explanation for the keto tautomer and the formation of the hydrates of compound
.
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Linearly bonded triiodide chains with fairly small distance between the adjacent iodine ions feature a facile electron transfer and highly anisotropic properties. Here, we demonstrate a novel ...strategy towards a new one-dimensional linear triiodide DMEDA·I
6
, using chain-type
N,N
′-dimethyl-ethanediamine (DMEDA) cation to coordinate triiodine ions. This triiodide has the shortest distance between adjacent I
3
and good linearity. An estimated electronic band gap of 1.36 eV indicates its semiconducting properties. 100 fold differences both in polarization-sensitive absorption and effective mass were achieved by simulation, with directions parallel and perpendicular to the
a
-axis of DMEDA·I
6
. The DME-DA·I
6
single crystal-based photodetectors show a good switching characteristic and a distinct polarization-sensitive photoresponse with linear dichroic photodetection ratio of about 1.9. Strongly anisotropic features and semiconducting properties of DMEDA·I
6
make this triiodide system an interesting candidate for polarization related applications.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Understanding the behaviour of heuristic search methods is a challenge. This even holds for simple local search methods such as 2-OPT for the Travelling Salesperson Problem (TSP). In this article, we ...present a general framework that is able to construct a diverse set of instances which are hard or easy for a given search heuristic. Such a diverse set is obtained by using an evolutionary algorithm for constructing hard or easy instances which are diverse with respect to different features of the underlying problem. Examining the constructed instance sets, we show that many combinations of two or three features give a good classification of the TSP instances in terms of whether they are hard to be solved by 2-OPT.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This study evaluated the interaction of Chrysanthemum indicum (CI) flavonoids (luteolin, acacetin, and buddleoside) with α‐amylase. Surface plasmon resonance (SPR) assay showed their equilibrium ...dissociation constants (KD) are 1.9695 ± 0.12, 2.9240 ± 0.20, and 3.2966 ± 0.08 mM at pH 6.0, respectively. Furthermore, their binding affinities were influenced by KCl, MgCl2, and CaCl2. Enzymatic kinetic studies revealed that three flavonoids exhibited noncompetitive α‐amylase inhibitory activity. The inhibitory sequence is luteolin > acacetin > buddleoside, which was in accordance with the results of binding affinity from SPR. 1,1‐diphenyl‐2‐picryl hydrazyl radical assay demonstrated that antioxidant activities of three flavonoids were inhibited significantly with α‐amylase. Meanwhile, the study reveals that hydroxyl on C′‐4, C′‐5, and C‐7 of flavonoids play an important role on the interaction of three flavonoids with α‐amylase. Also, SPR could be used as sensor for rapid screening inhibitors of α‐amylase and provide useful information for the application of C. indicum flavonoids in food and pharmaceutical area.
In this work, the kinetic constants, structure‐activity relationship, and influence factors of flavonoids and α‐amylase interaction were revealed. α‐Amylase activity and flavonoids antioxidant abilities were examined after interaction of flavonoids with α‐amylase.
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