The Protective Role of Non-Photochemical Quenching in PSII Photo-Susceptibility: A Case Study in the Field.

Non-photochemical quenching (NPQ) has been regarded as a safety valve to dissipate excess absorbed light energy not used for photochemistry. However, there exists no general consensus on the photoprotective role of NPQ. In the present study, we quantified the Photosystem II (PSII) photo-susceptibilities (mpi) in the presence of lincomycin, under red light given to five shade-acclimated tree species grown in the field. Photosynthetic energy partitioning theory was applied to investigate the relationships between mpi and each of the regulatory light-induced NPQ [Y(NPQ)], the quantum yield of the constitutive nonregulatory NPQ [Y(NO)] and the PSII photochemical yield in the light-adapted state [Y(PSII)] under different red irradiances. It was found that in the low to moderate irradiance range (50-800 µmol m-2 s-1) when the fraction of open reaction centers (qP) exceeded 0.4, mpi exhibited no association with Y(NPQ), Y(NO) and Y(PSII) across species. However, when qP < 0.4 (1,500 µmol m-2 s-1), there existed positive relationships between mpi and Y(NPQ) or Y(NO) but a negative relationship between mpi and Y(PSII). It is postulated that both Y(NPQ) and Y(NO) contain protective and damage components and that using only Y(NPQ) or Y(NO) metrics to identify the photo-susceptibility of a species is a risk. It seems that qP regulates the balance of the two components for each of Y(NPQ) and Y(NO). Under strong irradiance, when both protective Y(NPQ) and Y(NO) are saturated/depressed, the forward electron flow [i.e. Y(PSII)] acts as the last defense to resist photoinhibition.

Scalable Palladium-Catalyzed Alkoxycarbonylation of Conjugated Dienes.

The Pd(cod)Cl2-catalyzed alkoxycarbonylation of conjugated dienes to ß,γ-unsaturated esters was approached by both intramolecular phosphinesulfonate L1 and intermolecular PPh3/PTSA in this study. However, the poor solubility of the Pd/L1 complex and the labile monodentate Pd/PPh3 structure restricts the system efficiency, especially for the scale-up application. By contrast, the stable and well-soluble bidentate Xantphos system allows for the quantitative formation of 3-pentenoate (96%) on a gram scale within 6 h in weakly alkaline N-methylpyrrolidone (NMP), which also functions as a basic site to promote the rate-limiting alcoholysis step while reducing the dosage of ligand to a theoretical value.

Different photoprotective strategies for white leaves between two co-occurring Actinidia species.

At the outer canopy, the white leaves of Actinidia kolomikta can turn pink but they stay white in A. polygama. We hypothesized that the different leaf colors in the two Actinidia species may represent different photoprotection strategies. To test the hypothesis, leaf optical spectra, anatomy, chlorophyll a fluorescence, superoxide (O2 ˙- ) concentration, photosystem II photo-susceptibility, and expression of anthocyanin-related genes were investigated. On the adaxial side, light reflectance was the highest for white leaves of A. kolomikta, followed by its pink leaves and white leaves of A. polygama, and the absorptance for white leaves of A. kolomikta was the lowest. Chlorophyll and carotenoid content of white and pink leaves in A. kolomikta were significantly lower than those of A. polygama, while the relative anthocyanin content of pink leaves was the highest. Chloroplasts of palisade cells of white leaves in A. kolomikta were not well developed with a lower maximum quantum efficiency of PSII than the other types of leaves (pink leaves of A. kolomikta and white leaves of A. Polygama at the inner/outer canopy). After high light treatment from the abaxial surface, Fv /Fm decreased to a larger extent for white leaves of A. kolomikta than pink leaf and white leaves of A. polygama, and its non-photochemical quenching was also the lowest. White leaves of A. kolomikta showed higher O2 ˙- concentration compared to pink leaves under the same strong irradiance. The expression levels of anthocyanin biosynthetic genes in pink leaves were higher than in white leaves. These results indicate that white leaves of A. kolomikta apply a reflection strategy for photoprotection, while pink leaves resist photoinhibition via anthocyanin accumulation.

Highly Efficient Electrocatalytic CO2 Reduction to C2+ Products on a Poly(ionic liquid)-Based Cu0 -CuI Tandem Catalyst.

Electroreduction of CO2 on a polymer-modified Cu-based catalyst has shown high multi-electron reduction (>2 e- ) selectivity, however, most of the corresponding current densities are still too small to support industrial applications. In this work, we designed a poly(ionic liquid) (PIL)-based Cu0 -CuI tandem catalyst for the production of C2+ products with both high reaction rate and high selectivity. Remarkably, a high C2+ faradaic efficiency (FE C 2 + ) of 76.1 % with a high partial current density of 304.2 mA cm-2 is obtained. Mechanistic studies reveal the numbers and highly dispersed Cu0 -PIL-CuI interfaces are vital for such reactivity. Specifically, Cu nanoparticles derived Cu0 -PIL interfaces account for high current density and a moderate C2+ selectivity, whereas CuI species derived PIL-CuI interfaces exhibit high activity for C-C coupling with the local enriched *CO intermediate. Furthermore, the presence of the PIL layer promotes the C2+ selectivity by lowering the barrier of C-C coupling.

Observation of Transition from Ferroelasticity to Ferroelectricity by Solvent Selective Effect in Anilinium Bromide.

Organic ferroelectrics are highly desirable for their light weight, mechanical flexibility and biocompatibility. However, the rational design of organic ferroelectrics has always faced great challenges. Anilinium bromide (AB) has two structures reported in the Cambridge Crystallographic Data Centre, which might be an mmmF2/m type ferroelastic (AB-1). When we studied its ferroelasticity, we were surprised to discover that there was another crystal (AB-2) in H2 O besides this one, and they were very difficult to separate. By changing the solvent, we found that AB-1 crystals could be formed in ethanol, where ferroelastic domains were visualized by polarized light microscopy, and AB-2 crystals could be obtained from various crystallization solvents of methanol, isopropanol, N-butanol, acetonitrile, dimethyl sulfoxide, and N,N-dimethylformamide, which undergo a ferroelectric phase transition with mm2Fm, showing clear ferroelectricity in two phases. To our knowledge, the regulation of ferroelasticity to ferroelectricity by solvent selective effect is unprecedented in the field of ferroelectrics. This work reveals the important role of solvent effect in organic ferroelectrics.

Stabilization of Pb(II) in wastewater and tailings by commercial bacteria through microbially induced phosphate precipitation (MIPP).

Microbially induced phosphate precipitation (MIPP) is an effective and eco-friendly method for Pb(II) stabilization. The phosphate-solubilizing microorganisms (PSM) for MIPP are commonly isolated from Pb(II)-contaminated sites through a series of intricate and time-consuming enrichment and purification processes. This research used ready-made commercial bacteria to develop a simple MIPP process. Bacillus subtilis (BS, CCTCC AB 98002) was selected from two commercial PSM strains owing to more effective Pb(II) removal. Compared to the most isolated microorganisms, BS released more than twice as much inorganic phosphorus (Pi) as well as had a high-level Pb(II) tolerance. BS could remove >99% of Pb(II) from 500 mg/L Pb(II)-containing water at the optimal 0.05 M sodium glycerophosphate (SGP), pH 7-9, and ≤0.03 M MgCl2, outperforming most isolated microorganisms. In addition, BS could mitigate the contamination risk of the lead­zinc tailings, by reducing the readily leachable Pb(II) concentration from 0.81 mg/L (over the regulatory limit of 0.1 mg/L) to 0.00042 mg/L. The unstable Pb(II) in the solution and tailings was ultimately stabilized to Pb5(PO4)3Cl after the SGP phosphorlysis and phosphate precipitation processes. In conclusion, commercial BS is a superior alternative to isolated microorganisms for MIPP on Pb(II) stabilization. The simple-processed and high-effective BS-based MIPP provides the MIPP method a new insight for widespread implementation in the remediation of heavy metals-containing wastewater, soil, and waste.

Determination of mepiquat chloride in cotton crops and soil and its dissipation rates.

A simple, accurate and highly sensitive analytical method was developed in this study for determining the residues and dissipation dynamics of mepiquat chloride in soil and cotton crops (including plant and seed). The samples in this method were directly extracted with methanol-ammonium acetate solution and followed by analysis of high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The intra-day and inter-day recoveries of mepiquat chloride were in the range of 76.58-98.87 percent and 73.48-104.7 percent with relative standard deviations (RSDs) of 0.89-5.04 percent and 3.84-10.7 percent, respectively. The limit of quantification (LOQ) was 0.05mgkg(-1) for soil and 0.1mgkg(-1) for cotton plant and seed. The half-life of mepiquat chloride in cotton plants and in soil was 2.51-3.85 days and 7.56-10.50 days, respectively. The final residues of mepiquat chloride in all cotton seeds were below the MRLs of EU (5mgkg(-1)), Japan and America (2mgkg(-1)) over 14 days after the last spraying, and were below 1mgkg(-1) (the MRLs set by Argentina and Australia) over 21 days after the last spraying at recommended dosage. The final residues in soil were below the LOD (0.01mgkg(-1)) over 21 days after the last spraying.

[Oleanolic acid inhibits proliferation of HUVECs, and inhibits migration and tube formation via VEGF pathway].

To investigate the effects of oleanolic acid (OA) on the proliferation, migration and the formation of tube-like structure in human vascular endothelial cells (HUVECs). MTT assay, flat plate scarification, Transwell plates and matrigel-induced tube formation assay were performed to detect the effects of OA on proliferation, migration and tube formation. MTT assay showed that the inhibition rates of HUVECs treated with 60 and 100 microg x mL(-1) of OA for 24 h were 19% and 83% respectively. Treatment of HUVECs significantly inhibited the cell migration in a dose-dependent manner. The vascular indexes of HUVECs treated with 40 and 60 microg x mL(-1) OA were 33% and 20% respectively. Western blotting analysis showed that treatment of the cells with OA significantly attenuated the expression and secretion of VEGF. Additionally, VEGF could in part reverse the effects of OA on migration and tube formation of HUVECs. In conclusion, OA inhibits the proliferation, and VEGF plays an important role in OA induced decreased migration and tube formation of HUVECs.

Diaqua-bis-(1-methyl-1H-imidazole-κN(3))bis-[2-(naphthalen-1-yl)acetato-κO]cobalt(II).

In the title compound, [Co(C(12)H(9)O(2))(2)(C(4)H(6)N(2))(2)(H(2)O)(2)], the Co(II) ion is located on an inversion centre and displays a distorted octa-hedral coordination geometry. Two O atoms from two water mol-ecules and two carboxyl-ate O atoms from two 2-(naphthalen-1-yl)acetate ligands are in the equatorial plane and two N atoms from two 1-methyl-1H-imidazole ligands are in the axial positions. The structure is stabilized by intra-molecular O-H⋯O hydrogen bonds. Inter-molecular O-H⋯O hydrogen bonds link the complex mol-ecules into chains along [100].

Bis(1H-benzimidazole-κN(3))bis-[2-(naphthalen-1-yl)acetato-κ(2)O,O']nickel(II) monohydrate.

In the title compound, [Ni(C(12)H(9)O(2))(2)(C(7)H(6)N(2))(2)]·H(2)O, The Ni(II) cation is located on a twofold rotation axis and is six-coordinated in a distorted NiN(2)O(4) octa-hedral geometry. The asymmetric unit consists of a nickel(II) ion, one 2-(naphthalen-1-yl)acetate anion, a neutral benzotriazole ligand and one half of a lattice water mol-ecule. The crystal packing is stabilized by O-H⋯O and N-H⋯O hydrogen bonds. The title compound is isotypic with its Cd(II) analogue.

Pyrrolidin-1-ium 2-(naphthalen-1-yl)acetate-2-(naphthalen-1-yl)acetic acid (1/1).

In the title compound, C(4)H(10)N(+)·C(12)H(9)O(2) (-)·C(12)H(10)O(2), the pyrrolidine ring adopts an envelope conformation and the dihedral angle between the planes of the two naphthalene ring systems is 8.34 (10)°. The crystal structure is stabilized by O-H⋯O and N-H⋯O hydrogen bonds.

Electroreduction of carbon dioxide to multi-electron reduction products using poly(ionic liquid)-based Cu-Pd catalyst.

Electrocatalytic reduction of CO2 (CO2RR) to multi-electron (> 2e-) products provides a green and sustainable route for producing fuels and chemicals. Introducing the second metal element is a feasible strategy for "managing" the key intermediate on Cu-based materials to further improve the CO2RR catalytic performance. In this work, palladium, which promises the generation of CO, was introduced into the poly(ionic liquid)-based copper hybrid (Cu@PIL) to construct a novel Cu-Pd bimetallic electrocatalyst (Cu@PIL@Pd). Remarkably, with a small dosage of palladium (2.0 mol% compared with Cu), a high faradaic efficiency (FE) for C2+ products (68.7%) was achieved at -1.01 V (with respect to the reversible hydrogen electrode (RHE), the same below) with a high partial current density of 178.3 mA cm-2. Meanwhile, high selectivity towards CH4 (FE = 42.5%) and corresponding partial current density of 172.8 mA cm-2 were obtained on the same catalyst at -1.24 V, signifying a significant potential-dependent selectivity. Mechanistic studies reveal that both copper and palladium oxides are reduced to metallic states during the CO2RR. The presence of the adjoint copper phase and the highly dispersed electrostatic layer promote the generation of CO on the palladium components (both the PdO2 phase and the Pd(II) site). Besides, the local CO* was enriched by the significant diffusion resistance of CO in the PIL layer. The spillover of CO* from Pd sites to the adjoint Cu sites, accompanied by the increased local concentration of CO* around Cu sites, accounted for the observed good CO2RR catalytic performance, especially the high C2+ product selectivity.

Comparative chloroplast genome analysis of medicinally important Veratrum (Melanthiaceae) in China: Insights into genomic characterization and phylogenetic relationships.

Members of Veratrum are perennial herbs widely used in traditional Chinese medicine to induce vomiting, resolve blood stasis and relieve pain. However, the intrageneric classification and phylogenetic relationships within Veratrum have long been controversial due to the complexity of morphological variations and lack of high-resolution molecular markers. In this study, we reevaluated the infrageneric relationships with the genus Veratrum using complete chloroplast genome sequence data. Herein, the complete cp genomes of ten species of Veratrum were newly sequenced and characterized. The complete cp genomes of ten species of Veratrum had the typical quadripartite structure, ranging from 151,597 bp to 153,711 bp in size and comprising a total of 135 genes. The structure of Veratrum cp genomes (i.e., gene order, content, and genome components) was highly similar across species. The number of simple sequence repeats (SSRs) ranged from 63 to 78, and of long repeats ranged from 31 to 35. Eight highly divergent regions (ndhF, psbC-psbZ, psbK-psbI, rpoB-trnC_GCA, trnK_UUU-trnQ_UUG, trnS_GCU-trnG_UCC, trnT_UGU-trnL_UAA and ycf1) were identified and are potentially useful for the DNA barcoding of Veratrum. Phylogenetic analysis among 29 taxa based on cp genomes, total genes, protein-coding genes and intergenic regions strongly supported the monophyly of Veratrum. The circumscription and relationships of the infrageneric taxa of Veratrum were well-presented with great resolution. These results will facilitate the identification, taxonomy, and utilization of Veratrum plants as well as the evolutionary studies of Melanthiaceae.

Metal ion induced dual switchable dielectric and luminescent properties in hybrid halides.

A new multi-functional organic-inorganic hybrid compound was successfully obtained by regulating metal halides. Apart from excellent luminescence properties, in particular, the introduction of a Mn halide successfully achieved a dual-switchable dielectric property, which could lead to very interesting exploration in sensors.

Bromoxynil residues and dissipation rates in maize crops and soil.

A residue analytical method for the determination of bromoxynil in soil and maize was developed using high performance liquid chromatography with diode-array detector (HPLC-DAD) and high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The residual level and dissipation rate of bromoxynil in the soil and maize crops were determined using the established method. The mean half-life of bromoxynil in soil was 4.12 days with a dissipation rate of 91.25% over 21 days. The mean half-life in maize seedling was 1.14 days with a dissipation rate of 97.79% over 7 days. The final residues of bromoxynil were undetectable in maize grain, maize stem and soil at the harvest time, suggesting that residual levels of bromoxynil in maize plants are safe to humans and animals as well as to the environment.

Poly[[diaqua-µ(3)-citrato-praseodymium(III)] monohydrate].

In the coordination polymer, {[Pr(C(6)H(5)O(7))(H(2)O)(2)]·H(2)O}(n), seven of the nine coordination sites of the monocapped square-anti-prismatic geometry are occupied by three O atoms of the same citrate trianion (an O atom of the hy-droxy unit and the formally single-bond O atoms from two carboxyl units). Two other coordination sites are occupied by the O atoms of a chelating carboxyl unit of another citrate; one of these atoms is additionally involved in bridging. The seventh coordination site is occupied by the O atom of the formally double-bond O atom of a neighboring citrate. The remaining two coordination sites are occupied by water mol-ecules. The citrate functions in a µ(3)-bridging mode, connecting the metal atoms into a ribbon structure parallel to [010]. The structure is consolidated into a three-dimensional network by O-H⋯O hydrogen bonds.

4-Carb-oxy-anilinium chloride.

In the title salt, C(7)H(8)NO(2) (+)·Cl(-), the cation and anion are linked by an O-H⋯Cl hydrogen bond. The three-dimensional crystal structure is stabilized by N-H⋯O and N-H⋯Cl hydrogen bonds.

7-Hy-droxy-4-methyl-8-(3-methyl-benzo-yl)-2H-chromen-2-one ethanol monosolvate.

In the title compound, C(18)H(14)O(4)·C(2)H(6)O, the coumarin ring system is approximately planar with a maximum deviation of 0.037 (3) Šand is nearly perpendicular to the benzene ring, making a dihedral angle of 86.55 (9)°. In the crystal, mol-ecules are linked by classical O-H⋯O hydrogen bonds and weak C-H⋯O inter-actions.

Hexaaqua-cobalt(II) bis-(5-acetyl-2-hy-droxy-benzoate) dihydrate.

In the title compound, [Co(H(2)O)(6)](C(9)H(7)O(4))(2)·2H(2)O, the Co(2+) cation lies on a twofold rotation axis and is coordinated by six water mol-ecules in a distorted octa-hedral geometry. In the 5-acetyl-2-hy-droxy-benzoate anion, the hy-droxy group links with the carboxyl-ate group via an intra-molecular O-H⋯O hydrogen bond and the acetyl group is twisted to the benzene ring at a dihedral angle of 16.99 (12)°. In the crystal structure, the cations, anions and water mol-ecules are linked by extensive O-H⋯O hydrogen bonding.

Bis-(2-methyl-1H-imidazole-κN)bis[2-(naphthalen-2-yl)acetato-κO]copper(II).

In the crystal structure of the title compound, [Cu(C(12)H(9)O(2))(2)(C(4)H(6)N(2))(2)], the Cu(II) cations are square-planar coordinated by two 1-naphthyl-acetate anions and two 2-methyl-imidazole ligands into discrete complexes that are located on centres of inversion. These complexes are linked into chains parallel to [010] by inter-molecular N-H⋯O hydrogen bonding between the N-H H atom of the 2-methyl-imidazole ligands and the carboxyl-ate O atoms that are not involved in metal coordination.