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An enantioselective [4+1] spiroannulation of α-bromo-β-naphthols with azoalkenes has been developed for the one-step construction of a new class of pyrazoline-based spirocyclic molecules. Using chi...

The density, conductivity, and viscosity of the 1,3-dimethyl-2-imidazolinone and lithium nitrate (DMI– LiNO3) solvated ionic liquid were measured as a function of temperature. Additionally, the electrochemical mechanism and electrodeposition of neodymium from the DMI–LiNO3 solvated ionic liquid were investigated. Cyclic voltammetry results indicate that the electrochemical reduction of Nd(III) is irreversible and proceeds via one-step with three-electron transfer, which is controlled by diffusion with a diffusion coefficient of 5.08×10−8 cm2/s. Energy- dispersive X-ray spectrometry and X-ray photoelectron spectroscopy data confirm that the electrodeposit obtained after electrodeposition at −4 V (vs Ag) using the DMI–LiNO3–Nd(CF3SO3)3 solvated ionic liquid contains metallic neodymium.

Here, we investigate the role of SmERF73, a group VII ETHYLENE RESPONSE FACTOR stress response transcription factor, in the regulation of post-modification of the skeleton precursors of diterpene tanshinones in Salvia miltiorrhiza. Most genes found to be involved in tanshinone biosynthesis are located on chromosome 6, and five of these genes comprise a large gene cluster in S. miltiorrhiza. We found that SmERF73 overexpression in S. miltiorrhiza coordinately up-regulated the transcription of seven tanshinone biosynthetic genes, four of which were located in the tanshinone gene cluster, consequently increasing tanshinone accumulation, while SmERF73 silencing reduced corresponding gene transcription and tanshinone accumulation. SmERF73 recognizes GCC-box promoter elements of four tanshinone-associated genes (DXR1, CPS1, KSL1 and CYP76AH3) and activates their expression. Moreover, SmERF73 and its targets were up-regulated by stress elicitors; SmERF73 appears to be at least partly mediated by the jasmonic acid (JA) signaling pathway via interaction with SmJAZ3. SmERF73 coordinately regulates tanshinone biosynthetic gene expression, suggesting a potential link between tanshinone production and plant stress responses.

The two functional fluorinated ligands 2-fluoro-4-(1H-tetrazol-5-yl)benzoic acid (2-F-H2tzba) and 3-fluoro-4-(1H-tetrazol-5-yl)benzoic acid (3-F-H2tzba) were obtained by modifying 4-(1H-tetrazol-5-...

An unusual flower and tendril (uft) mutant in cucumber was caused by a mutation in Csa1G056950 encoding an F-box protein. Flowers and tendrils are important agronomic and yield traits of cucumber (Cucumis sativus L.). In this study, we identified an unusual flower and tendril (uft) mutant from an ethyl methanesulfonate (EMS) mutagenesis population. Genetic analysis revealed that the phenotype of the uft mutant was regulated by a single recessive nuclear gene. Map-based cloning and MutMap+ results demonstrated that Csa1G056950 (CsUFO), encoding an F-box protein, was the causal gene for the uft mutant phenotype of cucumber. A single nucleotide polymorphism (SNP) mutation (C to T) in the second exon of CsUFO resulted in premature translation termination. The expression level of CsUFO was significantly decreased in apical buds of the uft mutant compared with the wild-type (WT) WD1. Transcriptome analysis indicated that many genes for organ development were down-regulated in uft plants, suggesting CsUFO-associated networks that regulate flower and tendril development. These findings provide a new insight into understanding the molecular mechanisms of flower organogenesis in cucumber.

On the basis of an undeveloped asymmetrical pyridylcarboxylate ligand, 2-(2-carboxypyridin-4-yl)terephthalic acid (H3CPTA), an indium pyridylcarboxylate framework, [(Me)2NH2]1.5[In1.5(CPTA)2]·5.5NMF·6H2O (1), is synthesized under solvent thermal conditions. 1 displays a 3D anionic framework with a large void space, which contains open square channels with a cross section of 14.6 A and a pore surface decorated with carboxylic oxygen atoms. Depending on the anionic skeleton and high water stability, 1 exhibits high adsorption selectivity and capacity for cationic dyes in aqueous solution. Furthermore, the luminescence performance illustrates that 1 has selectivity and sensitivity to nitenpyram with good recyclability.

High-dose (HD) cisplatin remains the standard of care with chemoradiation for locally advanced oropharyngeal cancer (OPC). Cooperative group trials mandate bolus-HD (100 mg/m2 × 1 day, every 3 weeks) cisplatin administration at the beginning of the week to optimize radiosensitization-a requirement which may be unnecessary. This analysis evaluates the impact of chemotherapy administration day of week (DOW) on outcomes. We also report our institutional experience with an alternate dosing schedule, split-HD (50 mg/m2 × 2 days, every 3 weeks). We retrospectively reviewed 435 definitive chemoradiation OPC patients from 10 December 2001 to 23 December 2014. Those receiving non-HD cisplatin regimens or induction chemotherapy were excluded. Data collected included DOW, dosing schedule (bolus-HD vs split-HD), smoking, total cumulative dose (TCD), stage, Karnofsky Performance Status, human papillomavirus status and creatinine (baseline, peak and posttreatment baseline). Local failure (LF), regional failure (RF), locoregional failure (LRF), distant metastasis (DM), any failure (AF, either LRF or DM) and overall survival (OS) were calculated from radiation therapy start. Median follow-up was 8.0 years (1.8 months-17.0 years). DOW, dosing schedule and TCD were not associated with any outcomes in univariable or multivariable regression models. There was no statistically significant difference in creatinine or association with TCD in split-HD vs bolus-HD. There was no statistically significant association between DOW and outcomes, suggesting that cisplatin could be administered any day. Split-HD had no observed differences in outcomes, renal toxicity or TCD compared to bolus-HD cisplatin. Our data suggest that there is some flexibility of when and how to give HD cisplatin compared to clinical trial mandates.

A bifunctional ligand strategy for modification of the functional pores is of great significance in the structural design of metal-organic frameworks (MOFs). Herein, a new 2-fold interpenetrated "pillared-layer" 3D Co-MOF, {[Co(HL)(4,4'-bipy)]·DMF·2H2O}n (1), was successfully synthesized by using two kinds of ligands, imidazolecarboxylic acid and pyridine. The metal-carboxylic layers are pillared by the 4,4'-bipy ligand, displaying a 3D framework with rectangular 3D channels (high BET surface of 190.9 m2 g-1 and maximum aperture of 3.9 A) that are decorated with abundant uncoordinated N and O atoms. 1 shows good water stability and thermal stability (320 °C). The proper pores and active sites endowed 1 with a selective adsorption of Congo red in aqueous solution. In addition, a high CO2 adsorption capacity and an excellent CO2 chemical conversion were observed.

Separation or purification is one of the difficult problems in the petrochemical industry. To help solve the difficulty of separation or purification for C2H2/CO2 and C2Hn/CH4 in the chemical industry, we synthesized a new metal-organic framework (MOF), [Ni(dpip)]·2.5DMF·H2O (1), by a bipyridyl-substituted isophthalic acid ligand. The MOF includes two types of one-dimensional (1D) tubular channels with different sizes and porous environments. The unique tubular channels lead to not only remarkable gas sorption capacity of C2H4, C2H2, and CO2, but also good selectivity for C2H2/CH4, C2H2/CH4, CO2/CH4, and C2H2/CO2, as demonstrated by single-component sorption isotherm results, ideal adsorbed solution theory calculations, and dynamic breakthrough curves. Grand canonical Monte Carlo (GCMC) simulation reveals preferential adsorption sites in the MOF for CO2, C2H2, and C2H4. The MOF also exhibits an obvious size-selective absorption effect on vapor molecules.

In this paper, gas sensing characteristics of Boron-doped graphene oxide(B-GO) are presented firstly. In order to detect the optimal value of boron doping, different amounts of boron (5-30 wt%) are adopt in the doping process. The results of sensing test revealed that at room temperature (20 °C) and humidity (30%), 15 wt% B-GO has the optimal sensitivity to NH3. Meanwhile, the detection response and recovery time of B-GO gas sensor to NH3 are relatively short. Theoretical models of graphene and B-doped graphene are established, and energy change in the gas-adsorption of NH3 on the graphene oxide or B-doped graphene oxide is calculated. The enhanced sensing performance was ascribed to the B-doping and the formation of chemical bonds between boron and NH3.

Two new three-dimensional (3D) metal–organic frameworks (MOFs), namely {[Cu2(L)(4,4′-bipy)(OH)]·H2O}n (1) and {[Mn3(L)2(4,4′-bipy)(DMA)2]·H2O}n (2), were constructed by a newly synthesized thioether carboxylic acid ligand 5-((formic acid-3-sulfur)methyl)isophthalic acid (H3L) and 4,4′-bipyridine (4,4′-bipy). Thioether bonds in H3L can rotate freely in space, which are conducive in constructing MOFs with rich and stable structures. Simultaneously, the uncoordinated sulfur atoms affect the polarity of the framework and play an important role in adsorption. Gas adsorption results indicated that 1 can selectively adsorb CO2 from the mixture of CH4/CO2. Moreover, due to the high catalytic activity of [Cu4(COO)6N4O2] clusters, 1 is also an excellent recyclable catalyst that can chemically fix CO2 into cyclic carbonate under mild solvent-free conditions. Therefore, 1 may be explored as a dual-functional material for industrial adsorption and catalysis.

Developing highly efficient and low-cost electrocatalysts for the hydrogen evolution reaction (HER) in neutral media is crucial but still a significant challenge on account of the sluggish multistep reaction kinetics involved. Theoretically, constructing a metal/metal hydroxide interface with a metal hydroxide acting as a water dissociation promotor and a metal as the subsequent hydrogen adsorption site is expected to accelerate the HER kinetics in neutral media. We found that the intercalation of tungstate into Ni(OH)2 can tune the electronic structure of the Ni/Ni(OH)2 interface, decrease the energetic barrier for the Volmer step, and thus optimize the HER performance of Ni/Ni(OH)2 hybrid. Herein, a heterostructured Ni/Ni(OH)2 nanosheet array on Cu foam is designed and constructed via a simple hydrothermal and subsequent plasma reduction strategy. The HER performance can be further enhanced by assembling tungstate-intercalated Ni/Ni(OH)2 hybrid nanosheets on Cu2O nanotube arrays, exhibiting a low overpotential (39 mV @ 10 mA cm−2) and excellent stability (48 h).

A new multi-functional metal–organic framework, {[Cu2(HL)(H2O)2]·NMP·2H2O}n (1), was assembled by employing an asymmetrical V-shaped rigid multicarboxylic acid ligand H5L (H5L = 2,4-di(2′,5′-dicarboxylphenyl)benzoic acid) with Cu(II) ions. 1 possesses a 3D pore formed by two types of intersecting 1D cuboid channels. Moreover, owing to the abundant uncoordinated carboxylate O atoms decorated in the channels and open metal centers generated by the removal of coordinated water molecules, 1 exhibits a high CO2 adsorption capacity and significantly selective capture for CO2 over CH4. Hence, further research on the chemical fixation of CO2 is implemented, which reveals excellent heterogeneous catalytic activity. In addition, 1 displays particularly selective sorption towards the rhodamine B (RB) dye. Consequently, this study may provide a facile synthetic route for the construction of multi-functional materials.

Herein, we report a new 3D porous Co(II)-based metal–organic framework catalyst (Me2NH2)2[Co3(L)2(H2O)2]·2DMF (MOF I), which has been successfully prepared by using Co(II) ions and rigid V-shaped 3,5-di(2,4-dicarboxylphenyl)pyridine (H4L) via the solvothermal reaction. Structural analysis reveals that I displays a porous structure with the pore size of 16.2 × 7.2 A2 based on the trinuclear [Co3(COO)4(H2O)2N2] secondary building units (SBUs). Gas sorption experiments on the guest free sample I′ reveals a high capacity and selectivity to CO2 over CH4. And further, the catalytic explorations of the I′-catalyzed system (I′: 3 mol%; proline: 40 mol%; CH3CN: 2 mL) reveal that benzyl alcohols with different structures can be efficiently transformed into benzyl alcohols without by-products under mild conditions.

Suitable chemical components in water systems for human health are a crucial prerequisite for mankind's survival. Simple and effective innovations are being developed to efficiently monitor healthy and toxic substances. Here, with a hydrothermal technique, a novel thermostable metal–organic framework (MOF) [Cd2(L)(bib)0.5(H2O)3]n·1.75n(H2O) (MOF-1, H4L = biphenyl-2,3,3′,5′-tetracarboxylic acid, bib = 1,4-bis(imidazolyl)butane) was designed and synthesized. MOF-1 shows a 4,5-connection binodal 3D fsx-type topological net with irregular cages, which the bulk materials show high phase purity, excellent thermo/aqua-stability and intense fluorescence. The luminescent MOF was studied for the highly sensitive detection of trace amounts of Fe3+ ions and nitrobenzene and shows high KSV values of 4.653 × 104 and 5.724 × 104, respectively. It was also demonstrated that MOF-1 possesses superior probing ability towards nine other nitroaromatic explosives with remarkable quenching percentages. These results offer a new possibility for the potential multiple recognition of various chemical substances in human body and water systems by utilizing novel dual-functionalized luminescent MOF sensors.

A novel two-dimensional coordination polymer with a negatively charged framework named {[(CH3)2NH2][Zn2(L)2]·DMF}n (1) was solvothermally synthesized via the assembly of Zn(II) ions with the organic ligand H3L (2-(3,5-dicarboxylphenyl)-6-carboxyl-benzimidazole). 1 was characterized by IR spectroscopy, thermogravimetry, single-crystal, and powder X-ray diffraction methods. 1 possesses a 1D rectangle channel decorated by abundant uncoordinated imidazole N atoms and carboxylate O atoms, and is a better CO2 adsorbent and promising CO2/CH4 selective material, suggesting potential application in gas separation. Moreover, 1 can also serve as a multi-responsive sensing material for detecting nitrobenzene (NB) and Cr2O72−via a luminescence quenching effect with a low detection limit, and the mechanisms of the quenching effect and sensing properties of 1 are discussed in detail.

Two new metal–organic frameworks (MOFs), formulated as [Cd3(L)2(H2O)2]·2H2O (1) and [Zn2(L)(OH)(H2O)]·2DMA (2, DMA = N,N-dimethylacetamide), were first constructed via an unsymmetrical N-heterocyclic 5-((4-carboxypyridin-2-yl)oxy)isophthalic acid (H3L) ligand. Then, a proportion of the Zn(II) ions of 2 were substituted by fine-tuning the contents of Co(II) ions to obtain two new isomers, Co1-MOF 2 and Co2-MOF 2, the successful doping of which can be proved by PXRD, IR spectra, ICP, XPS, and SEM. The luminescent experiments suggested that complex 1 should be a good detector for detecting Fe3+ and Cr2O72− ions. More remarkably, the Co-rich MOF materials have increased gas capture for CO2 and CH4 compared to that of the Co-free isomer 2, and the absorption amount of CO2 and CH4 may rise with the increasing content of Co(II) ions in the system at higher pressure and lower temperature.

Considering the important applications and purification requirement of C2 hydrocarbons in the industry, the separation of C2 in mixtures is a vital task. To achieve this goal, herein a new Ni2+-based metal–organic framework (MOF) has been solvothermally prepared by utilizing a tetrazolyl-carboxyl ligand and 4,4′-bipyridine coligands as well as incorporating F− ions. The MOF shows a unique pillared-layer framework based on the novel metal–tetrazolate–carboxylate–fluorine chains, and possesses high chemical stability. Owing to the exposed adsorption sites of uncoordinated N atoms and F− ions in the channels, the MOF had high loadings for C2H2 and selectivity for C2H2 over C2H4, C2H6, CO2 and CH4. Under ambient conditions, dynamic breakthrough experiments revealed that the MOF performs effective separation of C2H2 from binary (C2H2–CH4, C2H2–C2H6, C2H2–C2H4, and C2H2–CO2) and ternary (C2H2–CO2–CH4, C2H2–C2H6–CH4, C2H2–C2H4–CH4, and C2H2–C2H4–C2H6) mixtures. The comparison based on the GCMC calculation revealed the crucial role of the accessible N and F sites for the selective capture of C2H2.

A new 3D luminescent Ba-organic framework {[Ba3L2(NMP)2(H2O)2]·2NMP·H2O}n (1) was first synthesized based on Ba(II) and a triangular-shaped bridging rigid ligand, namely 1,3,5-tris(4-carboxyphenly)benzene (H3L), via solvothermal reaction (NMP = N-methyl pyrrolidone), thereby forming a stabilized network including a one-dimensional (1D) infinite rod-like helical metal chain. 1 may be explored as a recyclable heterogeneous catalyst for the efficient fixation of CO2 to form serviceable cyclic carbonate since 1D channels remain decorated with abundant open metal sites (OMSs), and the catalytic efficiency of 1 was up to 98% for 1-bromo-2,3-propylene oxide. Simultaneously, the luminescence sensing shows that 1 has excellent response and sensitivity towards pollutants such as Fe3+, Cr2O72−, CrO42−, and [Fe(CN)6]3− ions. Moreover, 1 exhibits the particularly selective sorption towards the Congo red (CR) dye. Consequently, this study may provide a facile synthetic route for the construction of multi-functional Ba-MOF materials.

Assembly via 1,4-benzenedicarboxylate linker and Zn2+ ions afforded a new MOF containing novel [Zn4F4] cubane cores, showing excellent C2H2 separation from C2H2–CO2 and C2H2–CH4 mixtures.

Three isostructural lanthanide metal–organic frameworks (Ln-MOFs), {[Ln(L)(H2O)2]·H2O}n (M-Ln, Ln = Eu/Tb/Dy), were prepared with a flexible 3,5-(4-carboxybenzyloxy) benzoic acid (H3L) ligand and lanthanide ions by a solvothermal method. M-Ln are two-dimensional (2D) grid layer-stacking frameworks. M-Eu exhibits excellent chemical stabilities against organic solvents and shows strong luminescence. The experimental results indicated that M-Eu could be used as an ideal fluorescent probe to detect nitrobenzene (NB) in different solvents with a lower detection limit. M-Eu can also be used as a pH sensor because of its superior water stability. Furthermore, M-Eu and M-Tb show unique strong luminescence properties with high absolute quantum yields. The quantum yields can even reach up to 11.8% and 60.5%, respectively. Simultaneously, various kinds of heterometallic doped M-EuxTb1−x MOFs were acquired by tuning the ratios of Eu3+/Tb3+ ions, showing the unique color changes from red, orange-red, orange, orange-yellow, light yellow, yellow to green.

The separation of C2 hydrocarbon mixtures and VOCs is a very important and challenging process for industrial applications. Metal–organic frameworks (MOFs) have attracted extensive attention as an efficient separation material. In this study, a Dy-MOF {[(CH3)2NH2]2[Dy6(μ3-OH)8(FTZB)6(H2O)6]·(solvent)}n based on the construction of Dy6(μ3-OH)8(CO2)6(N4C)6 SBUs and F-H2tzba (2-fluoro-4-(1H-tetrazol-5-yl)benzoic acid) has been synthesized, which with a high-symmetry fcu topology contains two types of cages modified by free –F groups and uncoordinated tetrazolyl N atoms. The Dy-MOF exhibits high C2H2 and C2H4 storage and remarkable separation efficiency for C2H2–CH4, C2H4–CH4 and C2H2–C2H4 mixtures, as confirmed by breakthrough experiments. The MOF also shows significant selective adsorption ability for benzene/toluene and benzene/cyclohexane. The interactions between the MOF and the adsorbates were studied by molecular simulations.

Two new different metal–organic frameworks (MOFs) [Ba(L1)(H2O)2]n·nH2O (MOF 1) and [Ba(L2)(H2O)2]n·0.5nDMF·0.5nH2O (MOF 2) were yielded by the assembly of oxygen-friendly Ba(II) ions and two similar linkers, namely 2-(imidazol-1-yl)terephthalic acid (H2L1) and 2-(1H-1,2,4-triazol-1-yl) terephthalic acid (H2L2). Single-crystal X-ray diffractions (XRD) indicate that MOF 1 is a new three-dimensional (3D) stacking dense network formed by the one-dimensional (1D) rod-shaped chains and L1 linkers, whereas MOF 2 presents a 3D nanotube porous framework with cylindrical tunnels based on the 1D loop chains as the secondary building units (SBUs) by replacing the imidazole group in H2L1 with the triazole group in H2L2. As a result, MOF 2 has a higher density of active sites and Lewis acid sites in the porous surface of nanotube than MOF 1. Thereby, the CO2 capture and separation capacity of MOF 2 is great higher than that of CH4 at 298 K.

To help address efficient separation of CH light hydrocarbons and CH/CO in the chemical industry, the self-assembly via an azolate-carboxylate ligand and Co(II) ion gave rise to a new porous MOF material, [Co(btzip)(Hbtzip)]·2DMF·2HO () (Hbtzip = 4,6-bis(triazol-1-yl)isophthalic acid). In the MOF, the pores are modified by rich uncoordinated triazolyl Lewis basic N atoms and acidic -COOH groups, which strengthen interactions with CH hydrocarbons and CO molecules, leading to high adsorption amounts for CH CH, CH, and CO and remarkable separation efficiency for CH-CH, CO-CH, and CH-CO mixtures, as confirmed by breakthrough experiments on the realistic gas mixtures. The MOF also reveals outstanding selective adsorption ability for benzene/toluene, methanol/1-propanol, methanol/2-propanol, and 2-propanol/1-propanol isomers. Molecular simulations disclose the different adsorption sites in the MOF for various adsorbates.

Retinal segmentation is a prerequisite for quantifying retinal structural features and diagnosing related ophthalmic diseases. Canny operator is recognized as the best boundary detection operator so far, and is often used to obtain the initial boundary of the retina in retinal segmentation. However, the traditional Canny operator is susceptible to vascular shadows, vitreous artifacts, or noise interference in retinal segmentation, causing serious misdetection or missed detection. This paper proposed an improved Canny operator for automatic segmentation of retinal boundaries. The improved algorithm solves the problems of the traditional Canny operator by adding a multi-point boundary search step on the basis of the original method, and adjusts the convolution kernel. The algorithm was used to segment the retinal images of healthy subjects and age-related macular degeneration (AMD) patients; eleven retinal boundaries were identified and compared with the results of manual segmentation by the ophthalmologists. The average difference between the automatic and manual methods is: 2-6 microns (1~2 pixels) for healthy subjects and 3-10 microns (1~3 pixels) for AMD patients. Qualitative method is also used to verify the accuracy and stability of the algorithm. The percentage of “perfect segmentation” and “good segmentation” is 98% in healthy subjects and 94% in AMD patients. This algorithm can be used alone or in combination with other methods as an initial boundary detection algorithm. It is easy to understand and improve, and may become a useful tool for analyzing and diagnosing eye diseases.

Three-dimensional (3D) triply interlocked catenanes are a family of chemical topologies that consist of two identical, mechanically interlocked coordination cage components with intriguingly complex structures. Although only a few successful constructions of 3D interlocked catenanes have been achieved to date via metal-mediated assembly, these complex structures have thus far only been targeted by metal-nitrogen/oxygen coordination techniques. Here, taking advantage of rational ligand design, we report the efficient construction of a series of 3D triply interlocked [2]catenanes of the formula [Ag3L2]2, wherein the metal ions exclusively form bonds to N-heterocyclic carbene (NHC) units, and their subsequent transmetalation to the corresponding [Au3L2]2 gold analogues. The formation and transmetalation reactions proceed under mild conditions and are generally applicable. A series of characterization techniques were applied to confirm the formation and structure of the desired 3D triply interlocked architectures: multinuclear NMR spectroscopy, ESI-MS, and single-crystal X-ray diffraction analysis. The solid-state structure of [Ag3(1a)2]2(PF6)6 unambiguously confirms the existence of a 3D catenane that consists of two identical, mechanically interlocked trinuclear hexacarbene cage components. The interlocking of two 3D cages into a [2]catenane is driven by the efficient π···π stacking of triazine-triazine stacks with cooperative interactions between imidazo[1,5-a]pyridine subunits. Notably, the triply interlocked organometallic cages exhibit good stability toward various organic solvents, concentrations, and temperatures, and no disassembly occurred in the presence of coronene or pyrene. The future construction of mechanically interlocked architectures using metal-carbene bonds rather than metal-nitrogen bonds may provide assemblies with interesting properties for as-yet-unimagined applications in fields such as sensors and molecular electrical conductors.

Simultaneous attainments of high conductivity and superior catalysis are major challenges for amorphous electrocatalysts in carbon dioxide electroreduction at high overpotential. In this study, one protocol is first demonstrated to drive the shell amorphization of nanoporous Ag-Bi (a-NPSB) catalyst with the spatially interconnected ligament during the initial stage of CO2ER. This newborn a-NPSB bestows the outstanding catalysis, evidenced by a Faradaic efficiency of 88.4% for formate production at -1.15 V vs RHE, specific current density of 21.2 mA cm-2, and mass specific current density of 321 mA mg-1. The unique catalysis is considered as the collective contribution of the conductive ligament internally and amorphous Bi2O3 shell with about 3.2 nm thickness externally. Simultaneous obtaining of the conductivity of inner metals and catalytic activity of the amorphous shell will pave a new avenue for designing a robust electrode during electrochemical reaction.

The first isolable silylene-germylene complex 5 was assembled by a salt metathesis reaction between the germylene anion 3 and the N-heterocyclic chlorosilylene 4, and structurally characterized. The central structure of 5 demonstrates a remarkable gauche-bent geometry with the silylene and germylene units, which are interconnected by a Si-Ge bond with a length of 2.4498(9) A. This value is not only perceptibly longer than the distances known in doubly bonded germasilenes, and also slightly longer than those in germylsilanes. The DFT calculations on 5 confirmed a nearly nonpolar SiI -GeI single-bond nature and its bonding orbital, as well as the aromaticity of the C3 NGe-rings in 3 and 5. The latter increases the molecular stability of 3 and 5, and makes the preparation of silylene-germylene complex 5 a reality.

This work explores mechanical properties, structural evolution, and mechanism of creep-life enhancement for widely used P9 heat-resistant steel. The 17-year-on-site used P9 alloy exhibit a higher tensile strength and a smaller elongation than the new P9 alloy from room temperature to 700 °C. The P9 alloy also displays a typical ductile feature with a significantly necking profile. The P9 alloy shows phase transformation sequences of α-Fe (bcc) → A c 1 ∼ 858 ° C α + γ -Fe (bcc + fcc) → A c 3 ∼ 894 ° C γ-Fe (fcc) upon heating and γ-Fe (fcc) → M s ∼ 352 ° C martensite (bct) → M f ∼ 300 ° C martensite (bct) upon cooling. The new P9-alloy tube mainly contains ∼73.5% ferrite phase (α-Fe) and ∼26.5% carbide M3C. However, the used P9-alloy tube shows four crystalline phases including ∼45.9% ferrite, ∼14.5% martensite, ∼37.5% cementite (M3C) and ∼2.7% carbide M23C6. The creep test indicates that the used P9-alloy tube has a longer creep-life (or better anti-creep ability) than the new tube. Activation energies of atomic diffusion for the new and used tubes are respectively 252.45 and 345.87 kJ/mol, indicating a decreased diffusion capability in the used tube. This work suggests that martensite laths, lath boundaries, and precipitates (such as carbides) play important roles to inhibit creep-deformation in the P9-alloy steel.

With the aid of a pyridyl tetracarboxylate ligand, 2,5-bis(2',5'-dicarboxylphenyl)pyridine (H4L), two indium-organic frameworks, [In2(L)(OH)2]·2DMF·2H2O (1) and [Me2NH2][In(L)]·2.5NMF·4H2O (2), with (6,8)- and (4,4)-connected nets have been constructed in different solvent systems. Both 1 and 2 exhibit high thermal and chemical stability. Gas sorption behavior of 1 and 2 for N2, C2H2, C2H4, CO2, and CH4 indicate excellent separation selectivities of C2Hx/CH4 and CO2/CH4. Furthermore, 1 possesses a high density of Bronsted sites and shows efficient catalytic conversion for CO2 cycloaddition with epoxides. Meanwhile, luminescence investigations reveal that 2 can detect nitrofurazone efficiently.

The oxidation behavior of a newly designed Co–Ni-based alloy with varied addition of Ti (1.4 and 2.1 wt.%, hereafter referred as 1.4Ti and 2.1Ti alloys) was explored in air at 900 °C. It is found that an outer oxide layer composed of CoO, an intermediate oxide layer composed of intermittent TiO2 plus continuous Cr, W-rich oxides, and an inner oxidized region composed of Al2O3 were formed on the surface of 1.4Ti alloy, whereas the oxide structure of 2.1Ti alloy was composed of CoO as the outer oxide layer, continuous TiO2, Cr2O3, and WO3 as intermediate oxide layer, and Al2O3 as the inner oxidized region. With increasing Ti content, continuous TiO2 films formed in the intermediate oxide layer, which would lead to the formation of compact Cr2O3 and improved oxidation resistance after 100 h oxidation at 900 °C. These observations indicated that Ti addition can improve the high-temperature oxidation resistance of Co–Ni-based alloys.

The coordination preference of different metal ions and ligands have an immense influence on the constructions of functional MOF materials. In this work, two new monometallic complexes, namely [Ag(HL)(bipy)0.5 ] (1) and {[Tb(L)1.5 (H2 O)]⋅4 H2 O}n (2) (bipy=4,4-bipyridine), have been synthesized successfully by employing a bifunctional 2-(imidazol-1-yl)terephthalic acid (H2 L) ligand. After that, two new different heterometallic-organic frameworks (HMOFs), namely {[TbAg(L)2 (H2 O)3 ]⋅H2 O}n (3) and [TbAg(L)2 (H2 O)]n (4), were obtained from complexes 1 and 2 as the precursors based on a rational stepwise construction strategy and the theory of hard and soft acids and bases (HSAB principle), respectively. The HMOFs bearing dual metallic catalytic sites (Tb and Ag) can be used as heterogeneous catalysts without losing performance for the chemical fixation of CO2 with epoxides including the sterically hindered epoxides, demonstrating some of the highest reported catalytic activity values. This work may provide a new synthetic route toward tailoring new HMOFs with excellent catalytic activity.

Metal-organic frameworks (MOFs) with zeolitic structure process fantastic structural metrics and display excellent applications in many aspects; however, they are difficult to assemble. Herein, on the basis of a tetrahedral Zn

Purpose Gut microbiota affects various physiological functions in the host and has crucial effects on the nervous system. There is increasing evidence of a correlation between gut microbiota and depression; however, the mechanisms underlying the regulation of depression-like behavior by gut microbiota remain unclear. In this study, we assessed the regulatory mechanism of gut microbiota on depression-like behavior in rats. Methods We transplanted fecal microbiota obtained from patients with depression and healthy individuals into germ-free (GF) rats (n=18) through fecal microbiota transplantation technology. Next, we assessed the affective behavior in the rats using the forced swimming test and a sucrose preference test. We used enzyme-linked immunosorbent assay (ELISA) to determine the hippocampal levels of 5-hydroxytryptamine (5-HT), dopamine (DA), and noradrenaline (NE) and the serum levels of corticosterone (CORT), adrenocorticotropic hormone (ACTH), corticotropin-releasing hormone (CRH), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-6 (IL-6), interleukin-1 (IL-1), interleukin-1 (IL-4), and interleukin-1 (IL-10). The mitochondrial morphology of small intestinal epithelial cells was observed through transmission electron microscopy. Results Rats that received fecal microbiota from patients with depression (depression microbiota) exhibited depression-like behavior. They presented decreased levels of hippocampal neurotransmitters, serum CORT levels, and anti-inflammatory cytokine levels, as well as increased ACTH, CRH, and serum levels of multiple pro-inflammatory cytokines. Observation of the mitochondria ultrastructure showed damaged mitochondria in the intestinal epithelial cells, significant endoplasmic reticulum expansion, and border aggregation of nuclear chromatin. Conclusion Our findings suggested that the depression-like behaviors induced by the depression microbiota through the neuroendocrine-immune-mitochondrial pathway, which were associated with neuroendocrine disorders, inflammatory responses, and mitochondrial damage.

Based on the mixed carboxylate ligands synthesis strategy, an indium-organic framework, (Me2NH2)1.5[In1.5(FBDC)(BDC)]·2.5NMF·CH3CN (1) has been constructed by using the mixed (2,5-di(2',5'-dicarboxylphenyl)-difluorobenzene (H4FBDC) and terephthalic acid (H2BDC). Compound 1 contains a 3D intersecting pore system which surface is modified by F atoms, and it has excellent stability in pH = 2-12 aqueous solutions. The activated 1 shows high separation for C2H2/CO2 and C2H2/CH4. Moreover, 1 not only has strong luminescence but also has the high selectivity and sensibility of fluorescence detection to nitrofurazone (NZF) in antibiotic sensing experiments, which can be used as a luminescence sensor for NZF detection.

Three new pairs of 2-fold interpenetrated and self-entangled three-dimensional isostructural porous metal-organic frameworks (MOFs), [Zn(L1)(x)0.5]·0.5H2O (x = bipy for 1, bpa for 2, and bpe for 3) and [Zn(L2)(x)0.5]·0.5H2O (x = bipy for 4, bpa for 5, and bpe for 6) [bipy = 4,4'-bipyridine, bpa = 1,2-bis(4-pyridyl)ethylene, and bpe = 1,2-bis(4-pyridyl)ethylene], have been created and fine-tuned via similar skeleton ligands 2-(imidazol-1-yl)terephthalic acid (H2L1) and 2-(1H-1,2,4-triazol-1-yl)terephthalic acid (H2L2) and N-auxiliary coligands with different linking groups. Interestingly, the porosities of the MOFs can be effectively increased via the insertion of -CH2CH2- or -CH═CH- spacers into the N-auxiliary bipy ligand. As a result, complexes 5 and 6 displayed highly enhanced CO2 uptake capacities. Furthermore, complex 5 also had a higher C2/C1 selectivity as well as great CO2 cycloaddition efficiency.

Palladium-catalyzed alkene-directed cross-coupling of aryl iodide with another aryl halide through C-H arylation opens a unique avenue for unsymmetrical biaryl-derived molecules. However, homo-coupling of aryl iodides often erodes the overall synthetic efficiency. Reported herein is a highly chemoselective Pd0 -catalyzed alkyne-directed cross-coupling of aryl iodides with bromophenols, which was subsequently followed by phenol dearomatization to furnish a very attractive [2+2+1] spiroannulation. Notably, possible homo-coupling of aryl iodides was not observed at all. Mechanistic studies indicated that a five-membered aryl/vinyl palladacycle most likely accounts for promoting the key step of biaryl cross-coupling.

In this work, a new monometallic metal–organic framework (MOF), namely {[Pb2(L)2(H2O)]·H2O}n (1), was prepared via a N,O-mixed 2-(imidazol-1-yl)terephthalic acid (H2L) ligand and Pb(II) ions. Then, a first new porous d–p heterometallic MOF (HMOF), namely {[PbZn(L)2]·DMA·H2O}n (2), was yielded via Zn(II) ions and MOF 1 as the precursor because of the different coordination affinity of oxygen and nitrogen atoms with various metal ions. MOF 1 is a condensed packing motif, whereas HMOF 2 is a porous three-dimensional (3D) framework with unsaturated Pb(II) and Zn(II) active sites, uncoordinated carboxylate oxygen atoms and two kinds of porous channels due to the introduction of Zn(II) ions into the framework of MOF 1, which thus endowed HMOF 2 with excellent sorption and selectivity for CO2 over CH4. Moreover, HMOF 2 was explored to be an efficient heterogeneous catalyst for the fixation of CO2 with various epoxides because of the existence of the abundant unsaturated bimetallic sites as the Lewis acid. It is hoped that this work may supply an effective strategy to build plenty of d–p HMOF materials with excellent gas adsorption and catalytic properties.

In this study, two new monometallic organic frameworks (MOFs), namely {[Zn1.5L(NMP)(H2O)]·H2O}n (1) and {[Pb2L2(H2O)2]·H2O}n (2), were synthesized for the first time by a new bifunctional N,O-containing 2-(1H-tetrazol-5-yl)terephthalic acid (H2L) ligand. Then, based on the HSAB principle, another porous Pb–Zn heterometallic organic framework (HMOF), namely {[PbZn0.5L(H2O)]·0.5NMP·H2O}n (3), was successfully obtained for the first time by combining Pb(II) and Zn(II) ions with H2L. The MOFs 1 and 2 are 3D densely packed frameworks, whereas the HMOF 3 is a porous 3D framework (28.9% porosity) with 1D open channels modified by Lewis basic sites (exposed N atoms) and Lewis acidic sites (unsaturated bimetallic sites). The HMOF 3 has a strong boiling water/acid–base resistance (pH = 2–12) and shows an enhanced high-efficiency catalytic effect for CO2 conversion (98%) under ambient temperature and pressure conditions. In addition, fine color regulations of the MOFs were successfully realized by doping different kinds of metal ions into them. This study aims to provide a new way and field of vision for the construction of HMOFs and their multi-functional materials.

Carbon dioxide electroreduction provides a useful source of carbon monoxide, but comparatively few catalysts could be sustained at current densities of industry level. Herein, we construct a high-yield, flexible and self-supported single-atom nickel-decorated porous carbon membrane catalyst. This membrane possesses interconnected nanofibers and hierarchical pores, affording abundant effective nickel single atoms that participate in carbon dioxide reduction. Moreover, the excellent mechanical strength and well-distributed nickel atoms of this membrane combines gas-diffusion and catalyst layers into one architecture. This integrated membrane could be directly used as a gas diffusion electrode to establish an extremely stable three-phase interface for high-performance carbon dioxide electroreduction, producing carbon monoxide with a 308.4 mA cm−2 partial current density and 88% Faradaic efficiency for up to 120 h. We hope this work will provide guidance for the design and application of carbon dioxide electro-catalysts at the potential industrial scale., Here the authors deploy Ni single atom-decorated carbon membranes as integrated gas diffusion electrodes to construct an extremely stable three-phase interface for CO2 electroreduction, producing CO with a partial current density of 308.4 mA cm–2 and a Faradaic efficiency of 88% for up to 120 h.

Utilizing the self-assembly strategy between the paddle-wheel Cu2(COO)4 cluster and a terephthalic acid ligand modified by a triazolyl group, namely H2tztp = 2-(1H-1,2,4-triazol-1-yl)terephthalic acid, a porous MOF, [Cu0.5(tztp)0.5]·0.5DMA (1), has been successfully designed and built. 1 is a three-dimensional self-interpenerated framework with a (3,6)-connected rtl topology, and contains hydrophilic and hydrophobic channels decorated with rich uncoordinated triazolyl N atoms and benzene rings from tztp ligands, respectively. The unique porous environment leads not only to high gas adsorption amounts of CO2, C2H6, C2H4 and C2H2 but also to a good separation ability of C2 hydrocarbons over CH4, CO2 over CH4, and C2H2 over CO2 in the MOF. The specific adsorption sites of CO2 and C2 hydrocarbons were explored by a molecular simulation. The breakthrough experiments demonstrated excellent dynamic separations for CO2 and CH4, C2 hydrocarbons and CH4 as well as C2H2 over CO2. The MOF also revealed excellent adsorption and separation ability for CH3OH over other bulkier alcohol molecules.

The reaction of 2,5-di(2H-Tetrazol-5-yl)terephthalic acid (H4dtztp) and Cd2+ ions afforded a new three-dimensional (3D) honeycomb framework, [Me2NH2][Cd(dtztp)0.5(HCOO)]·1.5DMF·H2O (1). 1 contains a unique type of metal–carboxylate–azolate chain SBU and forms hexagonal tubular channels, as well as revealing high adsorption capacity for CO2 and C2H2, and significantly selective separation of CO2/CH4, C2H2/CO2 and C2H2/CH4. Molecular simulations were performed to study the interactions between the framework and gas molecules. Importantly, 1 shows good thermal stabilities (300 °C), mechanical stabilities and chemical stabilities in acidic (pH = 2) and basic (pH = 12) aqueous solutions. Meanwhile, the MOF as a heterogeneous catalyst can efficiently catalyze the cyclic addition reaction between CO2 and different epoxides to produce cyclic carbonates with high conversion yields. In addition, the selective adsorption of the MOF for benzene over cyclohexane was also studied.

In this study, we aimed to evaluate the toxic effects, changes in life span, and expression of various metabolism-related genes in Caenorhabditis elegans, using RNA interference (RNAi) and mutant strains, after 3-bromopyruvate (3-BrPA) treatment. C. elegans was treated with various concentrations of 3-BrPA on nematode growth medium (NGM) plates, and their survival was monitored every 24 h. The expression of genes related to metabolism was measured by the real-time fluorescent quantitative polymerase chain reaction (qPCR). Nematode survival in the presence of 3-BrPA was also studied after silencing three hexokinase (HK) genes. The average life span of C. elegans cultured on NGM with 3-BrPA was shortened to 5.7 d compared with 7.7 d in the control group. hxk-1, hxk-2, and hxk-3 were overexpressed after the treatment with 3-BrPA. After successfully interfering hxk-1, hxk-2, and hxk-3, the 50% lethal concentration (LC(50)) of all mutant nematodes decreased with 3-BrPA treatment for 24 h compared with that of the control. All the cyp35 genes tested were overexpressed, except cyp-35B3. The induction of cyp-35A1 expression was most obvious. The LC(50) values of the mutant strains cyp-35A1, cyp-35A2, cyp-35A4, cyp-35B3, and cyp-35C1 were lower than that of the control. Thus, the toxicity of 3-BrPA is closely related to its effect on hexokinase metabolism in nematodes, and the cyp-35 family plays a key role in the metabolism of 3-BrPA.

By incorporating the F substituent in tetrazolate–carboxylate ligands and combining the dipyridyl co-linkers, novel Zn-MOF, [(CH3)2NH2][Zn1.5(μ3-O)0.5(F-tzba)1.25(bpy)0.25(μ2-F)0.5]·2DMF·2H2O (1) (F-H2tzba = 2-F-4-(1H-tetrazol-5-yl) benzoic acid, bpy = 4,4′-bipyridine), was constructed. 1 was based on an unprecedented 12-connected hexanuclear cluster and formed an fcu topological framework, which contained intriguing 3D polar pores formed by intersected octahedral and tetrahedral cages with the modification using F. The framework not only showed high adsorption capacity for CO2, C2H2, and C2H6 but also exhibited excellent selective capture for CO2, C2H2, and C2H6 over CH4 and C2H2 over CO2 at 298 K. The framework as a Lewis acid heterogeneous catalyst also displayed highly efficient catalytic activity in the cycloaddition reaction of CO2 with different epoxides to produce cyclic carbonate chemicals. Grand canonical Monte Carlo simulations were studied to identify the different CO2, C2H2 and C2H6 binding sites as well as the catalytic interactions between the framework and the propylene oxide substrate. Simultaneously, the MOF could selectively adsorb the methylene blue (MB) dye from other organic dyes.

A mixed-ligand strategy has been used to construct stable luminescent coordination polymers (CPs). An ultra-stable Zn(ii) coordination polymer, [Zn(H3tpb)(Hbtc)]n (1) was hydrothermally synthesized by employing a new tripodal pyrazole ligand H3tpb and a classical carboxylic ligand H3btc (H3tpb = 1,3,5-tris(pyrazolyl)benzene, H3btc = 1,3,5-benzenetricarboxylic acid). Complex 1 exhibits a 2D sql network. Importantly, 1 not only possesses excellent thermal stability but also shows superior chemical stability in terms of water resistance, acid/base aqueous solutions tolerance (pH = 2-12), and organic solvents resistance. This excellent structural stability was further illustrated from the perspective of thermal decomposition kinetics. The luminescence properties were investigated, showing that complex 1 displays high sensitivity and selectivity for detecting Fe3+ and Cr2O72- ions in aqueous solutions via luminescence quenching effects.

Three new isostructural 3D lanthanide metal-organic frameworks (Ln-MOFs), {H[LnL(H2 O)]⋅2 H2 O}n (1-Ln) (Ln=Eu3+ , Gd3+ and Tb3+ ), based on infinite lanthanide-carboxylate chains were constructed by employing an ether-separated 5,5'-oxydiisophthalic acid (H4 L) ligand under solvothermal reaction. 1-Eu and 1-Tb exhibit strong red and green emission, respectively, through the antenna effect, as demonstrated through a combination of calculation and experimental results. Moreover, a series of dichromatic doped 1-Eux Tby MOFs were fabricated by introducing different concentrations of Eu3+ and Tb3+ ions, and they display an unusual variation of luminescent colors from green, yellow, orange to red. 1-Eu with channels decorated by ether O atoms and the open metal sites displays good performance for CO2 capture and conversion between CO2 and epoxides into cyclic carbonates.

The first isolable Ge5-spiropentadiene 1 was synthesized via the reduction of (iPr3Si)2NGeCl (3) with potassium. The crystal structure of 1 reveals a spirocyclic Ge5 skeleton containing two Ge-Ge double bonds (avg. 2.34 A), which are fettered in two Ge3 rings with a dihedral angle of 70.193°. The DFT calculations and orbital analysis show that the σ-delocalization of the Ge5 skeleton and the 2π-delocalized aromatic Ge3 rings enhance the stability of molecule 1.

Vegetables are an ideal source of human Se intake; it is important to understand selenium (Se) speciation in plants due to the distinct biological functions of selenocompounds. In this hydroponic study, the accumulation and assimilation of selenite and selenate in pak choi (Brassica rapa), a vastly consumed vegetable, were investigated at 1-168 h with HPLC speciation and RNA-sequencing. The results showed that the Se content in shoots and Se translocation factors with selenate addition were at least 10.81 and 11.62 times, respectively, higher than those with selenite addition. Selenite and selenate up-regulated the expression of SULT1;1 and PHT1;2 in roots by over 240% and 400%, respectively. Selenite addition always led to higher proportions of seleno-amino acids, while SeO42- was dominant under selenate addition (>49% of all Se species in shoots). However, in roots, SeO42- proportions declined substantially by 51% with a significant increase of selenomethionine proportions (63%) from 1 to 168 h. Moreover, with enhanced transcript of methionine gamma-lyase (60% of up-regulation compared to the control) plus high levels of methylselenium in shoots (approximately 70% of all Se species), almost 40% of Se was lost during the exposure under the selenite treatment. This work provides evidence that pak choi can rapidly transform selenite to methylselenium, and it is promising to use the plant for Se biofortification.