Search

Designing visible light photocatalysts with a metal oxide semiconductor as the starting material could expand a new horizon for the conversion and storage of solar energy. Here, the benchmark photocatalyst TiO2 was used to pursue this goal by anchoring aromatic acids. With benzoic acid (BA) as the initial molecule, horizontally extending one or two benzene rings furnishes 2-naphthoic acid (2-NA) and 2-anthracene acid (2-AA). Extending the aromatic acid was strategically deployed to design TiO2 complexes with violet light-induced selective aerobic oxidation of sulfide as the probe reaction. Moreover, triethylamine (TEA), an electron transfer mediator, was introduced to maintain the integrity of the anchored aromatic acids. Notably, there was a direct correlation between the π-conjugation of aromatic acid ligand and the selective aerobic oxidation of sulfides. Among the three aromatic acids, 2-AA delivered the best result over TiO2 due to the most extensive π-conjugated system. Ultimately, violet light-induced selective aerobic oxidation of sulfides into corresponding sulfoxides was conveniently realized by cooperative photocatalysis of 2-AA-TiO2 with 10 mol% of TEA. This work affords an extending strategy for designing the next-generation ligands for semiconductors to expand visible light-induced selective reactions.

Herein, a label-free, self-enhanced electrochemiluminescence (ECL) sensing strategy for divalent mercury (Hg(II)) detection was presented. First, a novel self-enhanced ECL luminophore was prepared by combining the ECL reagent tris(2, 2′-bipyridyl) dichlororuthenium(II) hexahydrate (Ru(bpy)32+) and its co-reactant carbon nitride quantum dots (CNQDs) via electrostatic interactions. In contrast to traditional ECL systems where the emitter and its co-reactant underwent an intermolecular reaction, the self-enhanced ECL system exhibited a shortened electron-transfer distance and enhanced luminous efficiency because the electrons transferred from CNQDs to oxidized Ru(bpy)32+ via an intramolecular pathway. Furthermore, the as-prepared self-enhanced ECL material was encapsulated in silica (SiO2) nanoparticles to generate a Ru-QDs@SiO2 luminophore. Based on the different affinity of Ru-QDs@SiO2 nanoparticles for single-stranded DNA (ssDNA) and Hg(II)-triggered double-stranded DNA (dsDNA), a label-free ECL biosensor for Hg(II) detection was developed as follows: in the absence of Hg(II), ssDNA was adsorbed on Ru-QDs@SiO2 surface via hydrogen bond, electrostatic, and hydrophobic interaction. Thus, quenched ECL signal was observed. On the contrary, in the presence of Hg(II), stable dsDNA was formed and carried the ssDNA separating from Ru-QDs@SiO2 surface, resulting in most of Ru-QDs@SiO2 existing in their free state. Therefore, a recovered ECL intensity was obtained. On this basis, Hg(II) was measured by the proposed method in the range of 0.1 nM-10 μM, with a detection limit of 33 pM. Finally, Hg(II) spiked in water samples was measured to evaluate the practicality of the fabricated biosensor.

Developing sensing platforms that simultaneously integrate high sensitivity and accuracy has been a promising but challenging task for the detection of protein biomarkers in clinical samples. Herein, we engineered an Au nanostar-based liquid phase interfacial ratiometric SERS platform with programmable entropy-driven DNA circuits to detect the protein biomarker Mucin 1 (MUC1) in clinical samples.

The spiro scaffold chiral organocatalyst of 3,2'-pyrrolidinyl spiro-oxindole amine was successfully prepared from racemic spiro-oxindole amine using l-menthol as a chiral pool in 4 steps in 28%-40% overall yields with at least 99% ee in scale-up preparation, and its catalytic activity was evaluated in the enantioselective aldol condensation between 3-(3-hydroxy-1H-pyrazol-1-yl)-oxindole and paraformaldehyde. The spiro organocatalyst showed superior catalytic activity and selectivity compared with its counterparts, and most substrates offered good to excellent results with up to 96% yield in 96% ee.

Solar photocatalysis is the key to resolve many environmental challenges but is usually hard to achieve over a metal oxide semiconductor. Therefore, assembling π-conjugated molecules onto semiconductors becomes an efficient approach to solar conversion via ligand-to-metal charge transfer. Here, a rational design of ligands for titanium dioxide (TiO2) is presented to produce robust visible light photocatalysts. Three hydroxynaphthoic acids (HNAs) were selected as ligands by extending an extra benzene ring of salicylic acid (SA) at 3,4 or 4,5 or 5,6 positions. These ligands could regulate the performance of TiO2 in which 2-hydroxy-1-naphthoic acid (2H1NA) endows the best outcome. In detail, blue light-powered cooperative photocatalysis of 2H1NA-TiO2 with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO, 5 mol%) inaugurates the expeditious formation of imines by oxidation of amines with atmospheric oxygen (O2). Interestingly, the increase of the O2 pressure from 1 atm to 0.4 MPa promoted the selective oxidation of benzylamine but thereafter declined with a further boost to 0.6 MPa. Notably, an electron transfer between the oxidatively quenched 2H1NA-TiO2 and TEMPO is established, offering a new pathway for environmental applications. This work presents a strategy in designing cutting-edge visible light photocatalysts via altering semiconductors with surface ligands.

Cellulose is the most widely distributed polymer material in nature and is considered a low-cost, green and recyclable material. Because of its excellent mechanical, optical and thermal properties, people are interested in the research of cellulose-based flexible electronic devices. Among them, bacterial cellulose has a low fiber bundle size during the production process and is easier to process to obtain nanofibers. Hereby, in this study the composite thermoelectric film was prepared from bacterial cellulose nanofibers (BCNFs) and copper iodide (CuI), a low-toxicity thermoelectric material. Hydrophobic properties of the composite thermoelectric film were obtained by immersing in AKD emulsion. It showed good mechanical flexibility and high biocompatibility. CuI particles can be recovered successfully through cellulase simulating the degradation process, and the closed-loop of preparation-recycling can be completed. In addition, it achieves an open circuit voltage of 11.3 mV and output power of 2.76 nW at a temperature difference of 70 K. This work not only confirms the environmental protection of CuI/BCNF thermoelectric film, but also provides a strategy for the recycling of thermoelectric equipment.

An albumin-binding CsA analogue 4MCsA was achieved by attachment of a thiol-reactive maleimide group at the side-chain of P4 position of CsA derivative. 4MCsA was semi-synthesized from CsA, and the cell-impermeability of albumin-4MCsA was detected by mass spectrometry and a competitive flow cytometry. 4MCsA exhibits inhibition of chemotaxis activity and inflammation by targeting extracellular CypA without immunosuppressive effect and cellular toxicity. These combined results suggested that 4MCsA can be restricted extracellularly through covalently binding to Cys34 of albumin with its maleimide group, and regulate the functions of cyclophilin A extracellularly.

Purple-fleshed sweetpotato (Ipomoea batatas（L.）Lam.) is rich in anthocyanins. R2R3-type MYB transcription factors（TFs）with EAR motifs inhibiting anthocyanin biosynthesis have been reported, and there is still a lack of information on how mutations in the EAR motifs of MYBs affect anthocyanin accumulation. In this study, we obtained three IbMYB44 TFs by bioinformatics. Among these TFs, IbMYB44.1, IbMYB44.3 with a complete EAR motif and IbMYB44.2 with a single amino acid mutant in the EAR motif caused an amino acid substitution from leucine to valine. RT-qPCR analysis showed that IbMYB44s was expressed at lower levels in the purple-fleshed sweetpotato than in nonpurple-fleshed sweetpotato (P 0.01). Transient expression assays showed that the inhibitory effect of IbMYB44.1/3 was stronger than IbMYB44.2 in tobacco leaves and red-skinned pears. RT-qPCR analysis further proved that IbMYB44.1/3 significantly inhibited the expression of anthocyanin biosynthesis-related genes compared with IbMYB44.2 in tobacco leaves and red-skinned pears. A dual luciferase reporter assay showed that IbMYB44s cannot directly activate the IbANS promoter, and the result was also verified by yeast one-hybrid (Y1H) experiments. Moreover, we identified the interaction of IbMYB340 with IbMYB44.1, IbMYB44.2 and IbMYB44.3 via yeast two-hybrid (Y2H) assays. Thus, IbMYB44.1/3 could interact with IbMYB340 to negatively regulate anthocyanin biosynthesis. This study enriched the regulatory network of anthocyanins and also provided a theoretical basis for a single amino acid mutant from leucine to valine in the EAR motif of IbMYB44.2 affecting anthocyanin biosynthesis in the purple-fleshed sweetpotato.

Transition metal and nitrogen co-doped carbon-based catalysts (TM-N-C) have become the most promising catalysts for Pt/C due to their wide range of sources, low cost, high catalytic activity, excellent stability and strong resistance to poisoning, especially Fe–N–C metal-organic frameworks (MOFs), which are some of the most promising precursors for the preparation of Fe–N–C catalysts due to their inherent properties, such as their highly ordered three-dimensional framework structure, controlled porosity, and tuneable chemistry. Based on these, in this paper, different iron sources were added to synthesis a sort of zeolitic imidazole frameworks (ZIF-8). Then the imidazole salt in ZIF-8 was rearranged into high N-doped carbon by high-temperature pyrolysis to prepare the Fe–N–C catalyst. We studied the physical characteristics of the catalysts by different iron sources and their effects on the catalytic properties of the oxygen reduction reaction (ORR). From the point of morphology, various iron sources have a positive influence on maintaining the morphology of ZIF-8 polyhedron. Fe–N/C–Fe(NO3)3 has the same anion as zinc nitrate, and can maintain a polyhedral morphology after high-temperature calcination. It had the highest ORR catalytic activity compared to the other four catalyst materials, which proved that there is a certain relationship between morphology and performance. This paper will provide a useful reference and new models for the development of high-performance ORR catalysts without precious metals.

Alcoholic liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD) are both serious chronic liver diseases worldwide. The cause of ALD is chronic alcoholism. NAFLD is a metabolic syndrome c...

Prediabetes is a prevalent metabolic disorder with multiple complications, including nonalcoholic fatty liver disease (NAFLD). In this study, we investigated the combinatorial effect of baicalein, a dietary flavonoid abundant in multiple edible plants, and acarbose on prediabetes-associated NAFLD. Baicalein and its metabolites inhibited de novo lipogenesis (DNL), thereby decreasing lipid accumulation and hepatokine secretion in oleic acid-induced hepatocytes. Carbohydrate restriction, which mimicked the effect of acarbose, led to comparable results. The combinatorial effect of baicalein and acarbose was further verified in prediabetic mice with NAFLD. Through the 16-week intervention, baicalein and acarbose inhibited DNL and improved glucose tolerance, oxidative stress, liver histology, and hepatokine secretion, thereby ameliorating insulin resistance and NAFLD. Our study demonstrated that baicalein enhanced the effect of acarbose on improving NAFLD and explored the underlying multitarget mechanism, laying a theoretical foundation for the development of flavonoid dietary supplements for the simultaneous improvement of NAFLD and prediabetes.

Attaching π-conjugated molecules onto TiO2 can form surface complexes that could capture visible light. However, to make these TiO2 surface complexes durable, integrating 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) or its analogues as a redox mediator with photocatalysis is the key to constructing selective chemical transformations. Herein, sodium 6,7-dihydroxynaphthalene-2-sulfonate (DHNS) was obtained by extending the π-conjugated system of catechol by adding a benzene ring and a substituent sodium sulfonate (-SO3 - Na+ ). The DHNS-TiO2 showed the best photocatalytic activity towards the blue light-induced selective aerobic oxidation of benzylamine. Compared to TEMPO, 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl (4-amino-TEMPO) could rise above 70% in conversion of benzylamine over the DHNS-TiO2 photocatalyst. Eventually, a wide range of amines could be selectively oxidized into imines with atmospheric O2 by cooperative photocatalysis of DHNS-TiO2 with 4-amino-TEMPO. Notably, superoxide (O2 •- ) is crucial in coupling the photocatalytic cycle of DHNS-TiO2 and the redox cycle of 4-amino-TEMPO. This work underscores the design of surface ligands for semiconductors and the selection of a redox mediator in visible light photocatalysis for selective chemical transformations.

Lithium-sulfur (Li-S) batteries are drawing huge attention as attractive chemical power sources. However, traditional ether-based solvents (DME/DOL) suffer from safety issues at high temperatures and serious parasitic reactions occur between the Li metal anodes and soluble lithium polysulfides (LiPSs). Herein, we propose a polysulfide-suppressed and flame-retardant electrolyte operated at high temperatures by introducing an inert diluent 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl (TTE) into the high-concentration electrolyte (HCE). Li dendrites are also efficiently suppressed by the formed LiF-rich protective layer. Furthermore, the shuttle effect is mitigated by the decreased solubility of LiPSs. At 60 °C, Li-S batteries using this nonflammable ether-based electrolyte exhibit a high capacity of 666 mAh g-1 over 100 cycles at a current rate of 0.2C, showing the greatly improved high-temperature performance compared to batteries with traditional ether-based electrolytes. The improved electrochemical performance across a range of temperatures and the enhanced safety suggest that the electrolyte has a great practical prospect for safe Li-S batteries.

A new binary ZnII coordination polymer, [Zn(2-cpa)(H2O)] n (2D-Zn) has been prepared by a 120 °C hydrothermal reaction of zinc(II) sulfate heptahydrate and 2-carboxy phenoxyacetic acid (2-H2cpa) in the presence of potassium hydroxide. Single-crystal X-ray diffraction analysis shows that the ZnII ion is located in a deformed ZnO6 octahedron bonded by one water and three 2-carboxy phenoxyacetate (2-cpa) ligands. The 2-cpa exhibits pentadentate double bridging chelate-μ 3 coordination mode and connects adjacent ZnII ions to generate a corrugated (4,4)-connected layer structure. The structures, conformation of 2-cpa and photoluminescence spectra for 2D-Zn have been carefully analyzed and compared with its two closely related compounds ̶ 1D [Zn(2-cpa)(H2O)] n (1D-Zn) and mononuclear [Zn(2-cpa)(H2O)3] (0D-Zn). The results showed that the conformation of 2-cpa in 2D-Zn has the maximum alteration and the corresponding fluorescence emission peak of 2D-Zn has the largest red-shift of 62 nm compared with that of free 2-H2cpa.

Pseudorabies virus (PRV), in the family Herpesviridae, is a pathogen of Aujeszky's disease, which causes great economic losses to the pig industry. Recent outbreaks of Pseudorabies imply that new control measures are urgently needed. The present study shows that kaempferol is a candidate drug for controlling PRV infection, as it possesses the ability to inhibit PRV replication in a dose-dependent manner in vitro. Kaempferol at a concentration of 52.40 µmol L−1 could decrease PRV-induced cell death by 90%. With an 50% inhibitory concentration (IC50) value of 25.57 µmol L−1 kaempferol was more effective than acyclovir (positive control) which has an IC50 value of 54.97 µmol L−1. A mode of action study indicated that kaempferol inhibited viral penetration and replication stages, decreasing viral loads by 4- and 30-fold, respectively. Addition of kaempferol within 16 h post infection (hpi) could significantly inhibit virus replication, and viral genome copies were decreased by almost 15-fold when kaempferol was added at 2 hpi. Kaempferol regulated the NF-κB and MAPKs signaling pathways involved in PRV infection and changed the levels of the target genes of the MAPKs (ATF-2 and c-Jun) and NF-κB (IL-1α, IL-1β and IL-2) signaling pathways. The findings of the current study suggest that kaempferol could be an alternative measure to control PRV infection.

Metal anodizations have attracted much attention, but the formation mechanisms of the porous anodic oxides are still unclear. Compared with the Ti anodization, the anodization of Zr is relatively less studied. In order to compare the anodizing processes of Ti and Zr, a comparative study of Ti and Zr was carried out under the different voltages of anodizing process in the same mixed electrolyte of ammonium fluoride and phosphate acid. It was found that the structure and morphology of their nanotubes were very different. The anodizing curve of Ti showed a state of constant current. However, the anodizing curve of Zr did not show the state of constant current and ZrO2 nanotubes were still formed. This indicates that there is no equilibrium between oxide growth and dissolution in the anodization. TiO2 nanotubes show an orderly array of nanotubes, but ZrO2 nanotubes have three kinds of composite structures: nanoflower, nanotube and dense films. By comparing the great difference of current-time curves between the two anodizing processes, the composite structure of ZrO2 nanotubes are interpreted reasonably by combining electronic current theory and oxygen bubble mold.

In recent years, chemodynamic therapy (CDT) has gained increasing interest in cancer treatment. In contrast to photodynamic therapy and sonodynamic therapy, extrinsic excitations such as laser or ultrasound are not required in CDT. As a result, the CDT performance is not limited by the penetration depth of the external irritation. However, CDT relies heavily on hydrogen peroxide (H2O2) in the tumour microenvironment (TME). Insufficient H2O2 in the TME limits the CDT performance, and the most reported methods to produce H2O2 in the TME are dependent on oxygen supply, which is restricted by the hypoxic TME. In this study, H2O2 self-providing copper nanodots were proposed, and the drug doxorubicin (DOX) was successfully loaded to construct DOX-nanodots. Our results showed that the nanodots produced H2O2 in the weakly acidic TME due to the peroxo group and further generated the most active hydroxyl radical (OH) through the Fenton-like reaction. This process was pH-dependent and did not occur in a neutral environment. In addition to OH, the nanodots also produced singlet oxygen (1O2) and superoxide anions (O2-) in the cancer cells. The copper nanodots performed promising CDT against breast cancer in vitro and in vivo, with enhanced cell apoptosis and decreased cell proliferation. The combination of chemotherapy and CDT using DOX-nanodots further improved the therapeutic effects. The treatments showed good biocompatibility with no obvious toxicity in major tissues, possibly due to the specific OH generation in the weakly acidic TME. In summary, the H2O2 self-providing copper nanodots in combination with DOX showed promising cancer-curing effects due to the oxygen-independent and tumour-specific production of reactive oxygen species and the cooperation of chemotherapy.

Recently, conjugated microporous polymers (CMPs) comprised of thiazolo[5,4-d]thiazole (TzTz) linkages have received much attention due to their excellent photoelectric properties. Herein, the polycondensation of dithiooxamide and benzyl aldehydes of C2, C3, and D2h symmetry afforded three TzTz-linked CMPs, namely TzTz-CMP-1, TzTz-CMP-2, and TzTz-CMP-3. Importantly, the porous and flexible characteristics of TzTz-linked CMPs enable the smooth selective aerobic oxidation of amines in ethanol (C2H5OH), a clean but redox-active solvent. All three TzTz-linked CMPs significantly surpass the benchmark mesoporous graphite carbon nitride (mpg-C3N4) photocatalyst. Intriguingly, TzTz-CMP-2 displays the best photocatalytic activity for the blue-light-mediated selective transformation of primary and secondary amines into imines. The conversions of amines were up to 90% with excellent selectivities for imines. This work highlights that CMPs with TzTz linkages may offer efficient photocatalytic selective transformations under genuinely ambient conditions.

Garlic leaf blight caused by Stemphylium eturmiunum was first reported in Jiangsu Province in China. The dicarboximide fungicide (DCF) procymidone is reported to possess broad-spectrum action in inhibiting filamentous fungi and is widely used to control leaf disease of various plants. Of 41 Stemphylium eturmiunum isolates collected in this study from commercial garlic farms in Pizhou and Dafeng counties of Jiangsu Province, eight isolates were resistant to procymidone. The following three phenotypes were categorized according to in vitro responses to DCFs: sensitive, low resistance to iprodione and procymidone, and high resistance to all iprodione and procymidone. The fitness of all resistant isolates was decreased in accordance with data on mycelial growth, conidiation, and virulence. After treatment with 10 µg/ml of procymidone for 4 h, mycelial intracellular glycerol concentrations of resistant isolates were significantly lower than those of sensitive isolates. Positive cross-resistance was observed between dicarboximides and phenylpyrroles, but there was no cross-resistance between dicarboximides and fluazinam or difenoconazole in the two resistant phenotypes. Nucleotide sequence alignment of two-component histidine kinase genes from sensitive and resistant isolates indicated that amino acid mutations were located at the histidine kinase, adenylyl cyclase, methyl-accepting chemotaxis protein and at the phosphatase domain of the N-terminal region and the response regulator domain of the C-terminal region. To our knowledge, this is the first report of DCF resistance in Stemphylium eturmiunum, and these findings will help establish a rational strategy to manage DCF-resistant populations of Stemphylium eturmiunum in the field.

Surface modification of nanoparticles with cellular protein components is a new biomimetic modification strategy, which utilizes the inherent affinity between homologous cells to introduce the same surface molecules into nanoparticles to improve the targeting performance. In this study, oleic acid (OA)-coated Fe3O4 nanocubes were prepared by a high-temperature thermal decomposition method and modified by 3, 4-dihydroxyphenylpropionic acid (DHCA); then, HeLa cell membranes were introduced onto the surface of the nanocubes through mixed coextrusion to try to endow them with the targeting function of natural cells. The results show that the prepared Fe3O4 nanocubes have high monodispersity, excellent water solubility, and biocompatibility. Moreover, the Fe3O4 nanocubes encapsulated by cellular protein show an obvious core-shell structure and the specific targeting property to HeLa cells is improved significantly, which is expected to be used in clinical targeted diagnosis and treatment of cancer.

Purpose: To investigate the gastroprotective effect of Alpinia conchigera rhizome in an ulcer rat model. Method: Sprague-Dawley rats were treated with ethanol extract of Alpinia conchigera at doses of 75 and 150 mg/kg body weight. After 28 days, the rats were sacrificed. Ulcer index, total acidity, pH, hemoglobin levels, and hemorrhagic lesions were determined through macroscopic assessment and histopathological examination. The levels of lipid peroxidation (LPO), superoxide dismutase (SOD), and catalase (CAT), and inflammatory markers (TNF-α, IL-1β, and IL-6) were also determined. Results: Alpinia conchigera significantly reduced ulcer index, total acidity, pH and hemoglobin levels (p < 0.05). Results from histology revealed that the extract protected the mucosa from lesions. Moreover, the extract significantly enhanced gastric mucosal activities of SOD and CAT, and decreased LPO levels and plasma concentrations of TNF-α, IL-1β, and IL-6 (p < 0.05). Conclusion: These results validate the traditional claims on the gastroprotective effects of Alpinia conchigera as revealed through its antioxidant and ulcer-healing properties by stimulation of important cellular mechanisms.

The development of a facile synthesis and controllable layer stacking approach for covalent organic frameworks (COFs) is an important issue for modulating their properties and realizing their application diversity. Herein, three COF isomers with different stacking models (eclipsed AA, staggered AB, and ABC stacking) were obtained by modulating the reaction temperature and solvent medium. Experimental and theoretical calculations show that the ABC stacking isomer obtained at room temperature is the kinetic product, while the AA stacking isomer prepared by the solvothermal method is a thermodynamic product. Owing to the tautomerism involved in the reaction process, these isomers possess different ratios of enol and keto forms. Thus, they exhibit different generation efficiencies of Type I and Type II reactive oxygen species (ROS). The ABC stacking isomers could be employed as metal-free heterogeneous photocatalysts for visible-light-induced oxidation of amines to imines, owing to the highest generation efficiency of Type I ROS.

The development of new techniques and materials that can separate ethylene from ethane is highly relevant in modern applications. Although adsorption-based separation techniques using metal-organic frameworks (MOFs) have gained increasing attention, the relatively low stability (especially water resistance) and unscalable synthesis of MOFs severely limit their application in real industrial scenarios. Addressing these challenges, we rationally designed and synthesized two new C2H6-selective MOF adsorbents (NKMOF-8-Br and -Me) with ultrahigh chemical and thermal stability, including water resistance. Attributed to the nonpolar/hydrophobic pore environments and appropriate pore apertures, the MOFs can capture C2 hydrocarbon gases at ambient conditions even in high humidity. The single-crystal structures of gas@NKMOF-8 realized the direct visualization of adsorption sites of the gases. Both the single-crystal data and simulated data elucidate the mechanism of selective adsorption. Moreover, the NKMOF-8 possesses high C2H6 adsorption capacity and high selectivity, allowing for efficient C2H6/C2H4 separation, as verified by experimental breakthrough tests. Most importantly, NKMOF-8-Br and -Me can be scalably synthesized through stirring at room temperature in minutes, which confers them with great potential for industrial application. This work offers new adsorbents that can address major chemical industrial challenges and provides an in-depth understanding of the gas binding sites in a visual manner.

Increasing drought stress resistance by exploiting crops’ potential is crucial for agricultural sustainable development. Alternate partial root-zone irrigation (PRI) shows some benefits in coping with drought stress, but there is limited information on physiological mechanism of crop in response to nitrogen supply patterns under alternate PRI. Therefore, we designed a rainproof-pond study to determine the effects of nitrogen supply methods on the physiological characteristics of maize (Zea mays L.) under alternate PRI. Two nitrogen fertilizer supply methods, including alternate nitrogen supply (AN) and conventional nitrogen supply (CN), were applied with alternate furrow irrigation (AI) and conventional furrow irrigation (CI), respectively. In addition, AIAN was applied in two ways, namely AIANS (supply of N fertilizer and irrigation water in a synchronized manner) and AIAND (supply of N fertilizer and irrigation water in a separate manner). Compared to CICN, AICN and AIANS enhanced leaf water use efficiency with a significant increase in transpiration rate, while photosynthetic rate was comparable. Also, compared to AIAND, the AIANS positively affected the most measured physiological characteristics. Greater leaf relative water content, chlorophyll and soluble protein content, and the activities of peroxidases and superoxide dismutase enzymes were found in AIANS and AICN. Moreover, the contents of malondialdehyde, proline, and soluble sugar decreased which can be attributed to enhanced root vitality in AICN and AIANS. Alternate furrow irrigation combined with conventional nitrogen supply or alternate synchronized nitrogen supply enhances the drought tolerance of maize by improving photosynthesis, antioxidant defense system, and osmoregulation.

In order to further understanding of how alga are adjusted to chromium(VI) toxicity at the level of photosynthesis, the pigment content and chlorophyll a (Chla) fluorescence parameters, were studied in Macrocystis pyrifera blades treated with 0, 0.5, 2, 10 and 20 mg/L Cr (VI) solution for 24 h. Results showed that these parameters were clearly affected by different concentrations of Cr (VI The pigment contents and Chla fluorescence parameters were clearly decreased in M. pyrifera exposed to 20 mg/L Cr (VI). Furthermore, the present study provided novel insights into Cr(VI) toxicity at the proteomic level using TMT-based technology after M. pyrifera was irrigated with 0 or 20 mg/L Cr(VI) solution for 24 h. The decreases in pigment content and Chl a fluorescence parameters resulted from alternations of the related proteins involved in pigment synthesis and photosynthetic processes. Expression of 227 different proteins was detected. Analysis of significant changes in KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways showed that M. pyrifera is able to reorganize its proteome in favor of photosynthesis, carbon fixation, metabolic pathways, oxidative phosphorylation, biosynthesis of amino acids, carbon metabolism, ribosome and biosynthesis of secondary metabolites under Cr(VI) stress. These findings could provide valuable information to elucidate the mechanism of Cr(VI) toxicity in M. pyrifera.

Ischemic stroke (IS) is a usual cerebrovascular ailment having high mortality and morbidity globally. The approaches for the treatment and prevention of cerebral ischemia–reperfusion injury (CIRI) are very limited. In this study, a delivery system of selenium nanoparticles loaded with gallic acid (GA-SeNPs) was developed utilizing ascorbic acid (AA) as a reducing agent and gallic acid (GA) as a capping agent. In pharmacokinetic study, GA-SeNPs clearly increases the AUC of the plasma concentration–time and extended GA half-life. In vitro effects of GA-SeNPs in the middle cerebral artery occlusion (MCAO) model and the oxygen glucose deprivation (OGD) model was measured. Finally, GA-SeNPs can be utilized as an efficient vehicle for delivery of GA in CIRI treatment.

A new N-alkylation Schiff base [N2,N6-bis(2-hydroxy-3-methoxybenzyl)pyridine-2,6-dicarboxamide] was synthesized from o-vanillin and pyridine-2,6-dicarboxamide by a solid-phase microwave green synthesis without catalyst and solvent. A new bismuth(III) complex was prepared by reaction of the ligand with BiCl3. The ligand and its bismuth(III) complex were characterized by elemental analysis, spectral techniques (1HNMR, MS, FT-IR and UV), chemical analysis, thermogravimetric analysis and molar conductance. The compositions of the ligand and its bismuth(III) complex were (C23H23N3O6) and Bi(C23H21N3O6)Cl. Moreover, the antibacterial activity of the ligand and its bismuth(III) complex against S. pombe was evaluated by bio-microcalorimetry at 32 °C. The quantitative relationship between some thermokinetic parameters (k, tG and I) with the concentration (c) of the ligand and its bismuth(III) complex was investigated. The half inhibition concentrations (IC50) of the ligand and its bismuth(III) complex were obtained as 4.63 × 10–3 mol dm−3 and 2.10 × 10–3 mol dm−3, respectively. The results showed that the antibacterial activity of bismuth(III) complex was stronger than that of the ligand. Further, the action target of bismuth(III) complex on bovine serum albumin (BSA) was studied by the molecular docking simulation method, and we found that bismuth(III) complex bounded at in the hydrophobic cavity of the substructure domain IIB of BSA.

Metal–organic framework (MOF)@graphene oxide (GO) composite material is a material with the advantages of GO and MOF, which can be an effective electromagnetic wave absorber. This study proposes a ...

Pb0.8Ba0.2ZrO3 (PBZ) nanofibers were prepared through electrospinning and mixed at a volume composite ratio of 0–6% with polyvinylidene fluoride (PVDF) dissolved in an organic solvent, and the PBZ/PVDF composite film was prepared through casting. The nanocomposites with PBZ nanofibers of 3 vol% showed the best ferroelectric performance in this work, and the maximum polarization value and breakdown field strength were 9.69 μC/cm2 and 420 MV/m, respectively. The dielectric constant and dielectric loss at a depolarization temperature of 285 K were 6.13 and 0.21, respectively. The performance of the electrocaloric effect was studied using the direct method near room temperature. Under 150 MV/m and − 30 °C, the △T and ΔS of the composite film were 13.99 K and 52.70 J/kg K, respectively. When the temperature increased to 70 °C, △T and ΔS become 5.08 K and 13.56 J/kg K, respectively. The simulation results and experiments indicate that the incorporation of nanofibers can increase the interface polarization with higher polarization value and improve the ferroelectric performance than pure PVDF.

Vibronic coupling is believed to play an important role in siglet fission, wherein a photoexcited singlet exciton is converted into two triplet excitons. In the present study, we examine the role of vibronic coupling in singlet fission using polarized transient absorption microscopy and ab initio simulations on single-crystalline pentacene. It was found that singlet fission in pentacene is greatly facilitated by the vibrational coherence of a 35.0 cm-1 phonon, where anisotropic coherence persists extensively for a few picoseconds. This coherence-preserving phonon that drives the anisotropic singlet fission is made possible by a unique cross-axial charge-transfer intermediate state. In the same fashion, this phonon was also found to predominantly drive the quantum decohence of a correlated triplet pair to form a decoupled triplet dimer. Moreover, our transient kinetic experimental data illustrates notable directional anisotropicity of the singlet fission rate in single-crystalline pentacene.

Mice of the C57BL/6ByJ (B6) strain have higher consumption of, and stronger peripheral neural responses to, sucrose solution than do mice of the 129P3/J (129) strain. To identify quantitative trait loci (QTLs) responsible for this strain difference and evaluate the contribution of peripheral taste responsiveness to individual differences in sucrose intake, we produced an intercross (F2) of 627 mice, measured their sucrose consumption in two-bottle choice tests, recorded the electrophysiological activity of the chorda tympani nerve elicited by sucrose in a subset of F2 mice, and genotyped the mice with DNA markers distributed in every mouse chromosome. We confirmed a sucrose consumption QTL (Scon2, or Sac) on mouse chromosome (Chr) 4, harboring the Tas1r3 gene, which encodes the sweet taste receptor subunit T1R3 and affects both behavioral and neural responses to sucrose. For sucrose consumption, we also detected five new main-effect QTLs Scon6 (Chr2), Scon7 (Chr5), Scon8 (Chr8), Scon3 (Chr9) and a sex-specific QTL Scon9 (Chr15), and an interacting QTL pair Scon4 (Chr1) and Scon3 (Chr9). No additional QTLs for the taste nerve responses to sucrose were detected besides the previously known one on Chr4 (Scon2). Identification of the causal genes and variants for these sucrose consumption QTLs may point to novel mechanisms beyond peripheral taste sensitivity that could be harnessed to control obesity and diabetes.

We have previously used crosses between C57BL/6ByJ (B6) and 129P3/J (129) inbred strains to map a quantitative trait locus (QTL) on mouse chromosome (Chr) 4 that affects behavioral and neural responses to sucrose. We have named it the sucrose consumption QTL 2 (Scon2), and shown that it corresponds to the Tas1r3 gene, which encodes a sweet taste receptor subunit TAS1R3. To discover other sucrose consumption QTLs, we have intercrossed B6 inbred and 129.B6-Tas1r3 congenic mice to produce F2 hybrids, in which Scon2 (Tas1r3) does not segregate, and hence does not contribute to phenotypical variation. Chromosome mapping using this F2 intercross identified two main-effect QTLs, Scon3 (Chr9) and Scon10 (Chr14), and an epistatically interacting QTL pair Scon3 (Chr9)–Scon4 (Chr1). Using serial backcrosses, congenic and consomic strains, we conducted high-resolution mapping of Scon3 and Scon4 and analyzed their epistatic interactions. We used mice with different Scon3 or Scon4 genotypes to understand whether these two QTLs influence sucrose intake via gustatory or postoral mechanisms. These studies found no evidence for involvement of the taste mechanisms, but suggested involvement of energy metabolism. Mice with the B6 Scon4 genotype drank less sucrose in two-bottle tests, and also had a higher respiratory exchange ratio and lower energy expenditure under basal conditions (when they had only chow and water available). Our results provide evidence that Scon3 and Scon4 influence mouse-to-mouse variation in sucrose intake and that both likely act through a common postoral mechanism.

A new and crucial synthon of 3-((diphenylmethylene)-amino)-oxindole was designed and synthesized, for which an organocatalytic and enantioselective Michael/cyclization reaction with a terminal vinyl ketone catalyzed by a cinchona base was disclosed. A wide variety (28 examples) of almost all new chiral spiro[oxindol-3,2'-pyrrols] were prepared in excellent yields (up to 99%) with excellent enantioselectivities (95-99% ee), of which a typical chiral spiro product was further reduced to chiral spiro[oxindole-3,2'-pyrrolidine].

Catalytic oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) have garnered great attention as the key character in metal-air batteries. Herein, we developed a superior nonprecious bifunctional oxygen electrocatalyst, fabricated through spatial confinement of Fe/Fe3C nanocrystals in pyridinic N and Fe-Nx rich carbon nanotubes (Fe/Fe3C-N-CNTs). During ORR, the resultant electrocatalyst exhibits positive onset potential of 1.0 V (vs. RHE), large half-wave potentials of 0.88 V (vs. RHE), which is more positive than Pt/C (0.98 V and 0.83 V, respectively). Remarkably, Fe/Fe3C-N-CNTs exhibits outstanding durability and great methanol tolerance, exceeding Pt/C and most reported nonprecious metal-based oxygen reduction electrocatalysts. Moreover, Fe/Fe3C-N-CNTs show a markedly low potential at j =10 mA/cm2, small Tafel slopes and extremely high stability for OER. Impressively, the Fe/Fe3C-N-CNTs-based Zn-air batteries demonstrate high power density of 183 mW/cm2 and robust charge/discharge stability. It is revealed that the spatial confinement effect can impede the aggregation and corrosion of Fe/Fe3C nanocrystals. Meanwhile, Fe/Fe3C and Fe-Nx play synergistic effect on boosting the ORR/OER activity, which provides an important guideline for construction of inexpensive nonprecious metal-carbon hybrid nanomaterials.

The relationship of immunoglobulin G (IgG) glycosylation with diabetes and diabetic nephropathy has been reported, but its role in diabetic retinopathy (DR) remains unclear. We aimed to investigate and validate the association of IgG glycosylation with DR.We analyzed the IgG N-linked glycosylation profile and primarily selected candidate glycans by lasso (least absolute shrinkage and selection operator) regression analysis in the discovery population. The findings were validated in the replication population using a binary logistics model. The association between the significant glycosylation panel and clinical features was illustrated with Spearman's coefficient. The results were confirmed by sensitivity analyses.Among 16 selected glycan candidates using lasso, two IgG glycans (GP15, GP20) and two derived traits (IGP32, IGP54) were identified and validated to be significantly associated with DR (P .05), and the combined adjusted odds ratios (ORs) were 0.587, 0.613, 1.970, and 0.593, respectively. The glycosylation panel showed a weak correlation with clinical features, except for age. In addition, the results remained consistent when the subjects with prediabetes were excluded from the controls, and the adjusted ORs were 0.677, 0.738, 1.597, and 0.678 in the whole population. Furthermore, in the 1:3 rematched population, a significant association was observed, apart from GP20.The IgG glycosylation profile, reflecting an aging and pro-inflammatory status, was significantly associated with DR. The variation in the IgG glycome deserves more attention in diabetic complications.背景: 免疫球蛋白G(IgG)糖基化与糖尿病和糖尿病肾病的关联已有研究报道, 但其在糖尿病视网膜病变(DR)中发挥的作用仍不清楚。本研究拟探讨IgG糖基化水平与DR的关联。 方法: 本研究对IgG N连接糖基谱进行检测, 基于Lasso方法在第一个人群中初步筛选糖基指标。应用逻辑回归模型在第二个人群中对候选糖基指标进一步验证, 并进行敏感性分析。糖基指标与临床特征间的相关性采用spearman系数衡量。 结果: 在16个候选糖基指标中, 2个直接糖基峰(GP15和GP20)和2个衍生糖基峰(IGP32和IGP54)最终被验证与DR相关, 汇总后的校正比值比(OR)分别为0.587、0.613、1.970、0.593。除年龄外, 糖基指标与临床特征呈现较弱的相关性。将糖尿病前期人群从对照人群中剔除后, 结果保持一致, OR值变为0.677、0.738、1.597、0.678。在1:3匹配的人群中, 除GP20外, 其余糖基指标均与DR存在显著关联。 结论: 反映衰老状态和促炎功能的IgG糖基化改变与DR存在显著关联。IgG糖基化修饰在糖尿病并发症发生发展中发挥的作用应受到更多关注。.

Background Endothelial dysfunction, a hallmark of diabetes, is a critical and initiating contributor to the pathogenesis of diabetic cardiovascular complications. However, the underlying mechanisms are still not fully understood. Ferroptosis is a newly defined regulated cell death driven by cellular metabolism and iron-dependent lipid peroxidation. Although the involvement of ferroptosis in disease pathogenesis has been shown in cancers and degenerative diseases, the participation of ferroptosis in the pathogenesis of diabetic endothelial dysfunction remains unclear. Aim To examine the role of ferroptosis in diabetes-induced endothelial dysfunction and the underlying mechanisms. Methods Human umbilical vein endothelial cells (HUVECs) were treated with high glucose (HG), interleukin-1β (IL-1β), and ferroptosis inhibitor, and then the cell viability, reactive oxygen species (ROS), and ferroptosis-related marker protein were tested. To further determine whether the p53-xCT (the substrate-specific subunit of system Xc-)-glutathione (GSH) axis is involved in HG and IL-1β induced ferroptosis, HUVECs were transiently transfected with p53 small interfering ribonucleic acid or NC small interfering ribonucleic acid and then treated with HG and IL-1β. Cell viability, ROS, and ferroptosis-related marker protein were then assessed. In addition, we detected the xCT and p53 expression in the aorta of db/db mice. Results It was found that HG and IL-1β induced ferroptosis in HUVECs, as evidenced by the protective effect of the ferroptosis inhibitors, Deferoxamine and ferrostatin-1, resulting in increased lipid ROS and decreased cell viability. Mechanistically, activation of the p53-xCT-GSH axis induced by HG and IL-1β enhanced ferroptosis in HUVECs. In addition, a decrease in xCT and the presence of de-endothelialized areas were observed in the aortic endothelium of db/db mice. Conclusion Ferroptosis is involved in endothelial dysfunction and p53-xCT-GSH axis activation plays a crucial role in endothelial cell ferroptosis and endothelial dysfunction.

Catalytic alkylation of benzene with ethanol has been considered as a sustainable alternative for producing ethylbenzene/diethylbenzene. This paper reports the promoted synthesis of hollow nano-sized (20–80 nm) ZSM-5 zeolite as excellent yet durable catalyst of benzene alkylation, which is achieved by adding N-methyl-2-pyrrolidone (NMP) and quaternary ammonium cationic hydroxyethyl cellulose (JR-400) in its synthesis gel during the synthesis. It is revealed by the ESI–MS and TEM characterization that the NMP promotes the dissolution–recrystallization of the ZSM-5 and a hollow structure is generated during the process. The JR-400 as special promoter further favors the formation of ordered nano-zeolite grain and suitable microstructure, confirmed by the molecular dynamic modeling and characterization. That action corporately contributed to the hollow nano-sized ZSM-5 zeolite that provided hierarchical porous structure and mild acid centers, as evidenced by the 129Xe and 1H NMR spectra. The obtained hollow zeolite ZSM-5 then exhibits enhanced catalytic activities and selectivity for benzene alkylation. Moreover, it also displays an extremely superior stability (deactivation rate constant, −0.06%/h) in the catalysis of benzene alkylation with ethanol. This behavior is attributed to its hierarchical porous structure (namely less diffusion resistance) and mild acid centers, which is beneficial to moderate the carbon deposition and then the catalyst deactivation. Those research results urge the JR-400-promoted synthesis as a facile strategy for the hollow nano-sized ZSM-5 with enhanced catalytic performance during the benzene alkylation with the ethanol.

Although simultaneous drought and cold stress occurs, especially in northwestern and eastern regions of China, and is an important factor limiting agricultural productivity, there are few studies focusing on plant responses to a combination of drought and cold stress. Here, by partially overlapping drought and cold stresses, we characterized the acclimation of maize (Zea mays B73) to these two stresses using physiological measurements, as well as comparative transcriptomics combined with metabolomics and hormonal analyses during the stress treatments and recovery stages. The combined drought and cold stress and drought stress alone were accompanied by a decline in photosynthetic capacity and enhanced transcriptional response, and subsequent recovery of these following removal from stress, whereas cold stress alone was accompanied by irreversible damage to photosynthetic capacity and chloroplast structure. The stress combination induced transcription-associated metabolomic alterations, in which raffinose, trehalose-6-phosphate, and proline accumulated, and monosaccharide abundance increased. Concomitantly, the increased abscisic acid (ABA) content and upregulated ABA signaling pathway may have provided the transcriptional regulation for the metabolic changes. In a parallel experiment, ABA treatments prior to exposure of the plants to cold stress primed the plants to survive the cold stress, thus confirming a key role for the endogenous ABA activated by the drought pretreatment in acclimation of the plants to cold. We present a model showing that the plant response to the combined stress is multi-faceted and reveal an ABA-dependent maize acclimation mechanism to the stress combination.

The separator is a key component of the lithium-ion battery (LIB), which not only prevents the anode and the cathode from contacting, but is also related to the performance of the LIB. However, the widely used polyolefin separator has the disadvantages of inferior electrolyte retention capability and poor electrolyte wettability. Therefore, the development of high-performance separators for LIB has attracted widespread attention. In order to enhance the electrolyte retention capacity of the separator, the bacterial cellulose (BC)/zeolitic imidazolate framework-67 (ZIF-67) composite separator was prepared by introducing ZIF-67 on the BC nanofibers. It was found that the introduction of ZIF-67 in BC membrane significantly improved the pore structure and enhanced the electrolyte retention capability, thus contributing to the transfer of lithium-ion, increasing the ionic conductivity (0.837 mS cm−1). In terms of ionic conductivity, BC/ZIF-67 separator has achieved a great improvement compared to polypropylene (PP) separator (0.096 mS cm−1). Besides, the prepared BC/ZIF-67 composite separators hardly shrink at high temperatures. The discharge capacity retention of the LIB using BC/ZIF-67 separator was 91.41% after 100 cycles (0.2 C). Meanwhile, LIB with BC/ZIF-67 separator showed a large discharge capacity (156 mAh g−1) and improved rate performance. Therefore, the BC/ZIF-67 composite membrane has good development potential in the direction of LIB separator.

Background Saussurea involucrata survives in extreme arctic conditions and is very cold-resistant. This species grows in rocky, mountainous areas with elevations of 2400–4100 m, which are snow-covered year-round and are subject to freezing temperatures. S. involucrata’s ability to survive in an extreme low-temperature environment suggests that it has particularly high photosynthetic efficiency, providing a magnificent model, and rich gene pool, for the analysis of plant cold stress response. Fructose-1, 6-bisphosphate aldolase (FBA) is a key enzyme in the photosynthesis process and also mediates the conversion of fructose 1, 6-bisphosphate (FBP) into dihydroxyacetone phosphate (DHAP) and glycerol triphosphate (GAP) during glycolysis and gluconeogenesis. The molecular mechanisms underlying S. involucrata’s cold tolerance are still unclear; therefore, our work aims to investigate the role of FBA in plant cold-stress response. Results In this study, we identified a cold-responsive gene, SiFBA5, based on a preliminary low-temperature, genome-wide transcriptional profiling of S. involucrata. Expression analysis indicated that cold temperatures rapidly induced transcriptional expression of SiFBA5, suggesting that SiFBA5 participates in the initial stress response. Subcellular localization analysis revealed that SiFBA5 is localized to the chloroplast. Transgenic tomato plants that overexpressed SiFBA5 were generated using a CaMV 35S promoter. Phenotypic observation suggested that the transgenic plants displayed increased cold tolerance and photosynthetic efficiency in comparison with wild-type plants. Conclusion Cold stress has a detrimental impact on crop yield. Our results demonstrated that SiFBA5 positively regulates plant response to cold stress, which is of great significance for increasing crop yield under cold stress conditions.

Supplemental Digital Content is available in the text., Aim To evaluate neuroprotective efficacy of fisetin against the experimental model of spinal cord injury (SCI). Materials and methods SCI was induced in male Sprague-Dawley rats by placing an aneurysm clip extradurally. Rats were treated either with vehicle or fisetin for 28 days after SCI. Results Treatment with fisetin significantly attenuated SCI-induced alternations in mechano-tactile and thermal allodynia, hyperalgesia and nerve conduction velocities. SCI-induced upregulated tumor necrosis factor-alpha, interleukins, inducible nitric oxide synthase, cyclooxygenase-II, Bcl-2-associated X protein and caspase-3 mRNA expressions in the spinal cord and these were markedly reduced by fisetin. Spinal nuclear factor kappa B and nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor-alpha protein levels were also significantly downregulated by fisetin. Hematoxylin and eosin staining of spinal cord suggested that fisetin significantly ameliorated histological aberrations such as neuronal degeneration, necrosis and inflammatory infiltration induced in it. Conclusion Fisetin exerts neuroprotection via modulation of nuclear factor kappa B/nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor-alpha pathway by inhibiting release of inflammatory mediators (inducible nitric oxide synthase and cyclooxygenase-II), proinflammatory cytokines (tumor necrosis factor-alpha and interleukins), apoptotic mediators (Bcl-2-associated X protein and caspase-3).

Exocrine pancreas abnormalities are increasingly recognized as features of type 1 diabetes. We previously reported reduced serum trypsinogen levels and in a separate study, smaller pancreata at and prior to disease onset. We hypothesized that three pancreas enzymes (amylase, lipase and trypsinogen) might serve as serological biomarkers of pancreas volume and risk for type 1 diabetes. Amylase, lipase, and trypsinogen were measured from two independent cohorts, together comprising 800 serum samples from single-autoantibody positive (1AAb+) and multiple-AAb+ (≥2AAb+) subjects, individuals with recent-onset or established type 1 diabetes, their AAb negative (AAb-) first-degree relatives, and AAb- controls. Lipase and trypsinogen were significantly reduced in ≥2AAb+, recent-onset, and established type 1 diabetes subjects versus controls and 1AAb+, while amylase was reduced only in established type 1 diabetes. Logistic regression models demonstrated trypsinogen plus lipase (AUROC=81.4%) performed equivalently to all three enzymes (AUROC=81.4%) in categorizing ≥2AAb+ versus 1AAb+ subjects. For Cohort 2 (n=246), linear regression demonstrated lipase and trypsinogen levels could individually and collectively serve as indicators of BMI-normalized relative pancreas volume (RPVBMI, PBMI and may improve disease staging in pre-type 1 diabetes.

CuI-Functionalized materials show high potential in numerous applications such as adsorptive desulfurization. Nonetheless, the instability of CuI against oxidation limits its practical applications, and exposure of CuI to air can lead to the formation of CuII owing to the presence of oxygen and moisture. Herein, an unexpected way to stabilize CuI against oxidation was designed by constructing a superhydrophobic microenvironment in original hydrophilic metal–organic frameworks (MOFs) via polystyrene (PS) coating. A pre-polymerization strategy is developed to coat PS on the surface of CuI-functionalized MIL-101(Cr) (CuIM) rather than entering the pores (producing CuIM@PS), and the access of moisture to CuI is hindered, thus stabilizing CuI regardless of the existence of oxygen. CuI in CuIM@PS is stable in the air with a constant relative humidity of 75% for 200 days, while almost all CuI is converted to CuII in CuIM in only 14 days. The optimal CuIM@PS material after air exposure can adsorb 0.208 mmol g−1 of thiophene, which is much superior to that of CuIM (0.024 mmol g−1) despite the comparable adsorption capacity for unexposed materials. Moreover, the present CuIM@PS adsorbents exhibit excellent adsorption performance for water-containing model fuels.

Dye-semiconductor assemblies are very versatile visible light photocatalysts in terms of tunability by tweaking either dye molecules or semiconductor materials. Here, we adopted a strategy of molecular inverse design of alizarin red S (ARS) to identify the blueprint underlying the superior photocatalytic activity of ARS-TiO2 assembly. We discovered that the substituted -OH groups of anthraquinone provide visible light absorption and binding sites. Importantly, the molecular features of 1,2-dihydroxyanthraquinone (1,2-DHA) contributes mostly to the unique photocatalytic activity after binding with TiO2 with broad visible light absorption which can be maintained at high concentration of amines. Moreover, the electron-withdrawing effect of -SO3-Na+ groups increase the acidities of substituted -OH groups, leading to stronger binding and subsequent higher activity. Ultimately, in situ formed 1,2-DHA-TiO2 assembly can be a powerful photocatalyst for green light-induced selective oxidation of amines into imines with aerial O2. This work makes evident the promise of molecular design in tailoring dye-semiconductor assemblies for visible light-induced photocatalytic selective chemical transformations.

Two-dimensional crystalline covalent triazine frameworks (2D-CTFs) are emerging 2D materials with the characteristics of fully annulated conjugated structures and aromatic nitrogen-rich skeletons. Due to the difficulty in the control of the polymerization dynamics, the preparation of crystalline 2D-CTFs is still a daunting challenge compared to that of other organic framework materials. Herein, we report the construction of crystalline 2D-CTFs using dual modulator control, in which aniline and a co-solvent are used as dual modulators for a dynamic covalent linkage formation and non-covalent self-assembly process, respectively. The strategy successfully leads to crystalline CTFs from different functional building blocks. The crystalline CTFs could be further regulated via peripheral functionalization, which dramatically boosted the photocatalytic activity for oxidation of sulfides into sulfoxides, and excellent conversion rates and selectivity for a wide range of sulfides with various functional groups were achieved after functionalization with methoxyl groups. This work gives new insights into the design and synthesis of crystalline CTFs for photocatalytic applications.

The assembly of TiO2 surface with π-conjugated molecules can give rise to an apparent red-shift of its optical absorption band, and subsequently engender ligand-to-metal charge transfer (LMCT) triggered by visible light. However, the application of LMCT remains elusive due to the vulnerability of these π-conjugated molecules at the vicinity of reactive centers. Therefore, extending the π-conjugation of these molecules could be envisioned to overcome this bottleneck with the oxidation of sulfides as a probe reaction. With salicylic acid (SA) as the starting molecule, extending the benzene ring at 5,6 or 3,4 positions with another one afforded 2-hydroxy-1-naphthoic acid (2H1NA) and 1-hydroxy-2-naphthoic acid (1H2NA). Compared to SA, 2H1NA showed a moderate improvement, while 1H2NA caused a significant enhancement for modifying anatase TiO2 to conduct the selective aerobic oxidation of sulfides triggered by blue light with (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) as a redox mediator. Ultimately, the aerobic oxidation of organic sulfides to corresponding sulfoxides in CH3OH could be achieved by the 1H2NA–TiO2 photocatalyst in cooperation with TEMPO. This study introduces the assembly of extended π-conjugated molecules on TiO2, which may pave the way to construct more efficient visible-light photocatalysts.

A metal-free and oxidant-free procedure for the sulfonylation of Baylis–Hillman acetates with sulfonyl hydrazides under the irradiation of visible light and open-air conditions at room temperature is described. This transformation has high yields (up to 92%), excellent stereoselectivity, broad substrate scope, good functional group tolerance, and mild reaction conditions. Moreover, mechanistic studies indicate that a sulfonyl radical pathway is involved in this reaction.