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The water oxidation half-reaction at anodes is always considered the rate-limiting step of overall water splitting (OWS), but the actual bias distribution between photoanodes and cathodes of photoelectrochemical (PEC) OWS cells has not been investigated systematically. In this work, we find that, for PEC cells consisting of photoanodes (nickel-modified n -Si [Ni/ n -Si] and α-Fe2O3) with low photovoltage (V ph < 1 V), a large portion of applied bias is exerted on the Pt cathode for satisfying the hydrogen evolution thermodynamics, showing a thermodynamics-controlled characteristic. In contrast, for photoanodes (TiO2 and BiVO4) with V ph > 1 V, the bias required for cathode activation can be significantly reduced, exhibiting a kinetics-controlled characteristic. Further investigations show that the bias distribution can be regulated by tuning the electrolyte pH and using alternative half-reaction couplings. Accordingly, a volcano plot is presented for the rational design of the overall reactions and unbiased PEC cells. Motivated by this, an unbiased PEC cell consisting of a simple Ni/ n -Si photoanode and Pt cathode is assembled, delivering a photocurrent density of 5.3 ± 0.2 mA cm−2. [ABSTRACT FROM AUTHOR]

Copper (Cu) has been widely used for catalyzing the CO2 reduction reaction (CO2RR), but the plasmonic effect of Cu has rarely been explored for tuning the activity and selectivity of the CO2RR. Herein, we conducted a quantitative analysis on the plasmon-generated photopotential (Ehv) of a Cu nanowire array (NA) photocathode and found that Ehv exclusively reduced the apparent activation energy (Ea) of reducing CO2 to CO without affecting the competitive hydrogen evolution reaction (HER). As a result, the CO production rate was enhanced by 52.6% under plasmon excitation when compared with that under dark conditions. On further incorporation with a polycrystalline Si photovoltaic device, the Cu NA photocathode exhibits good stability in terms of photocurrent and syngas production (CO : H2 = 2 : 1) within 10 h. This work validates the crucial role of the plasmonic effect of Cu on modulating the activity and selectivity of the CO2RR. [ABSTRACT FROM AUTHOR]

High‐efficient photoelectrocatalytic direct ammonia oxidation reaction (AOR) conducted on semiconductor photoanodes remains a substantial challenge. Herein, we develop a strategy of simply introducing ppm levels of Cu ions (0.5–10 mg/L) into NH3 solutions to significantly improve the AOR photocurrent of bare BiVO4 photoanodes from 3.4 to 6.3 mA cm−2 at 1.23 VRHE, being close to the theoretical maximum photocurrent of BiVO4 (7.5 mA cm−2). The surface charge‐separation efficiency has reached 90 % under a low bias of 0.8 VRHE. This AOR exhibits a high Faradaic efficiency (FE) of 93.8 % with the water oxidation reaction (WOR) being greatly suppressed. N2 is the main AOR product with FEs of 71.1 % in aqueous solutions and FEs of 100 % in non‐aqueous solutions. Through mechanistic studies, we find that the formation of Cu−NH3 complexes possesses preferential adsorption on BiVO4 surfaces and efficiently competes with WOR. Meanwhile, the cooperation of BiVO4 surface effect and Cu‐induced coordination effect activates N−H bonds and accelerates the first rate‐limiting proton‐coupled electron transfer for AOR. This simple strategy is further extended to other photoanodes and electrocatalysts. [ABSTRACT FROM AUTHOR]

Female infertility represents a major challenge for improving the production efficiency in the dairy industry. Historically, fertility has declined whereas milk yield has increased tremendously due to intensive genetic selection. In vivo evidence reveals about 60% pregnancy loss takes place during the first month following fertilization. Meanwhile, early embryo development is significant for somatic cell nuclear transfer in cattle as a large proportion of cloned embryos fail to develop beyond peri-implantation stage. Oocyte quality is of utmost importance for the early embryo to develop to term for both fertilized and cloned embryos. Epigenetic reprogramming is a key process occurring after fertilization and critical roles of epigenetic modifiers during preimplantation development are now clear. Incomplete epigenetic reprogramming is believed to be a major limitation to cloning efficiency. Treatment of cloned embryos with epigenetic modifying drugs (e.g., Trichostatin A) could greatly improve cloning efficiency in both mice and cattle. Recently, the rapid progress in high-throughput sequencing technologies has enabled detailed deciphering of the molecular mechanisms underlying these events. The robust efficiency of genomic editing tools also presents an alternative approach to the functional annotation of genes critical to early development.

Soil salinization is a prevalent global environmental issue that significantly hampers crop growth and yield. However, there has been limited research on the impact of nitrogen fertilization and various management practices in alleviating saline-sodic stress in crops. In order to examine the impact of combined straw and nitrogen fertilizer application on the physiological and photosynthetic characteristics of rice in saline-sodic paddy fields, a three-year field experiment was conducted in Jilin Province, China. The experiment was conducted as a split-zone trial, where the main zone consisted of straw (S) and the secondary zone consisted of nitrogen fertilizer (N). Two levels of straw were 0 t ha−1 (B) and 7 t ha−1 (T). Four nitrogen treatments were applied: 0, 150, 250, and 350 kg ha−1, denoted as N0, N1, N2, and N3, respectively. The results show that the combination of straw and nitrogen fertilizer has been found to effectively reduce the Na+/K+ value, malondialdehyde content, and the relative electric leakage of rice leaves in saline-sodic soil. Furthermore, it increases leaf water potential, relative water content, and chlorophyll content, thereby promoting rice photosynthesis and improving rice yield. The rice yield exhibited the greatest positive effect when straw and nitrogen fertilizer were combined at a rate of 250 kg ha−1. The effectiveness of this combination improves over time. However, it is important to avoid excessive application of nitrogen fertilizer when using straw returning. This approach not only ensures stable rice yield in saline-sodic fields, but also has positive effects on the economic impact of fertilizer application and soil environment preservation. [ABSTRACT FROM AUTHOR]

Combined elemental deficiencies are more complex and insidious physiological metabolic responses than single elemental stresses. To determine the effects of phosphorus (P), iron (Fe), zinc (Zn), and their deficient combinations on photosynthetic characteristics of rice seedlings, we investigated their effects on dry weight, chlorophyll (Chl) content, rapid photosynthetic carbon assimilation CO2 responses, and Chl fluorescence in four-week-old rice (CB9 and BJ1 cultivars) seedlings. The results showed that the dry matter, maximum carboxylation efficiency (Vc,max), and maximum electron transfer efficiency (Jmax) of seedlings were all reduced to different degrees under the element deficiency treatments. JIP-test analysis showed that the decrease in the concentration of active PSII reaction centers (RC/ABS) under -Zn treatment was the main reason for the inhibition of performance index PIABS. The -P treatment reduced RC/ABS and inhibited electron transfer (ψEo). Primary photochemical reactions (φPo) of -P-Zn treated seedlings were also inhibited compared to the -P treatment. The -Fe and -Fe-Zn treatments inhibited photosynthesis most severely, which not only reduced RC/ABS but also severely inhibited φPo and ψEo. Notably, the -P-Fe and -P-Fe-Zn treatments of the CB9 improved the RC/ABS, alleviating the limitation of Fe deficiency. These results help enhance the understanding of the complex relationship between nutrient balance and photosynthesis, especially for P, Fe, Zn, and their combined deficiency. [ABSTRACT FROM AUTHOR]

Copper (Cu) has been widely used for catalyzing the CO 2 reduction reaction (CO 2 RR), but the plasmonic effect of Cu has rarely been explored for tuning the activity and selectivity of the CO 2 RR. Herein, we conducted a quantitative analysis on the plasmon-generated photopotential ( E hv ) of a Cu nanowire array (NA) photocathode and found that E hv exclusively reduced the apparent activation energy ( E a ) of reducing CO 2 to CO without affecting the competitive hydrogen evolution reaction (HER). As a result, the CO production rate was enhanced by 52.6% under plasmon excitation when compared with that under dark conditions. On further incorporation with a polycrystalline Si photovoltaic device, the Cu NA photocathode exhibits good stability in terms of photocurrent and syngas production (CO : H 2 = 2 : 1) within 10 h. This work validates the crucial role of the plasmonic effect of Cu on modulating the activity and selectivity of the CO 2 RR.

High-efficient photoelectrocatalytic direct ammonia oxidation reaction (AOR) conducted on semiconductor photoanodes remains a substantial challenge. Herein, we develop a strategy of simply introducing ppm levels of Cu ions (0.5-10 mg/L) into NH 3 solutions to significantly improve the AOR photocurrent of bare BiVO 4 photoanodes from 3.4 to 6.3 mA cm -2 at 1.23 V RHE , being close to the theoretical maximum photocurrent of BiVO 4 (7.5 mA cm -2 ). The surface charge-separation efficiency has reached 90 % under a low bias of 0.8 V RHE . This AOR exhibits a high Faradaic efficiency (FE) of 93.8 % with the water oxidation reaction (WOR) being greatly suppressed. N 2 is the main AOR product with FEs of 71.1 % in aqueous solutions and FEs of 100 % in non-aqueous solutions. Through mechanistic studies, we find that the formation of Cu-NH 3 complexes possesses preferential adsorption on BiVO 4 surfaces and efficiently competes with WOR. Meanwhile, the cooperation of BiVO 4 surface effect and Cu-induced coordination effect activates N-H bonds and accelerates the first rate-limiting proton-coupled electron transfer for AOR. This simple strategy is further extended to other photoanodes and electrocatalysts., (© 2023 Wiley-VCH GmbH.)

Electrocatalytic oxidation of organics using water as the oxygen source is a prospective but challenging method to produce high-value-added chemicals; especially, the competitive oxygen evolution reaction (OER) limits its efficiency. Herein, a tandem catalysis strategy based on a single-atom catalyst with Cr atoms atomically dispersed at a CoSe 2 support (Cr 1 /CoSe 2 ) is presented. Thereinto, Co and Cr sites are endowed with a specific function to activate water and styrene respectively, and the competition between the OER and styrene oxidation is turned into mutual benefits via cooperated active sites. Under a potential of 1.6 V Ag/AgCl , excellent selectivity of 95% to benzaldehyde and a high conversion rate of styrene at 88% without any exogenous oxidizing reagent are achieved. Isotopic tracing, isotope-labeled in situ Raman spectra, and detailed theoretical calculation further reveal the tandem mechanism, showing that the transfer of *OOH intermediates from the Co to the Cr sites serves as a bridge to link the oxidation of water and styrene. This work develops a new strategy for the co-oxidation of multi-species based on tandem catalysis, providing novel insights for the design of single-atom catalysts., (© 2022 Wiley-VCH GmbH.)

A naked-eye colorimetric chemosensor DK based on benzothiazole could recognize CN - effectively. When DK interacted with CN - in the aqueous solution, the obvious color change of the solution was directly observed by the naked eye. Other anions did not cause any interference. It is interesting that DK could also discriminate Ni 2+ from other cations, and the possible interaction mode between them was verified based on the Job's plot, 1 H nuclear magnetic resonance titration, infrared , electrospray ionization mass spectrometry, scanning electron microscopy analysis, and density functional theory calculation methods. As a result, it is clear that the mode of action between DK and CN - was different from that between DK and Ni 2+ . Meanwhile, the limit of detection of DK toward CN - and Ni 2+ was calculated to be 1.7 × 10 -8 or 7.4 × 10 -9 M, respectively. In addition, CN - was recognized qualitatively by a test paper and silica gel plates made from DK . DK was able to detect CN - in tap water quantitatively, rapidly, and on-site by the use of a smartphone APP. All results implied that DK has certain prospects for practical application to identify CN - in water., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)

To study the chemical constituents of Ardisia punctata, compounds were isolated with a combination of multi-chromatography. Their structures were determined on the basis of spectral analysis and comparison to those of the known compounds. A 1,4-benzoquinone derivative and a alkylphenol were isolated from the petroleum ether extract of the roots of Ardisia punctata. Their structures were elucidated as 2-tridecyl-3-[(2-tridecyl-4-acetoxy-6-methoxy)-phenoxyl] -6-methoxy-1,4-benzoquinone (1) and 2-methoxy-4-hydroxy-6-tridecyl-phenyl acetate (2). The two compounds are both new.

Aim: To study the chemical constituents of Ardisia punctata., Methods: Compounds were separated with a combination of multi-chromatography. Their chemical structures were determined on the basis of spectral analysis and single crystal X-ray diffraction., Results: Three compounds were isolated from chloroform extract of the roots of Ardisia punctata. Their structures were elucidated as 2-tridecyl-3-[(2-tridecyl-3-acetoxy-4-methoxy-6-hydroxy) -phenyl]-6-methoxy-1, 4-benzoquinone (1), 2-tridecyl-3-[(2-tridecyl-4,6-dihydroxy) -phenyl]-6-methoxy-1,4-benzoquinone (2) and 2-tridecyl-3-[(2-pentadecyl-4,6-dihydroxyl) -phenyl]-6-methoxy-,4-benzoquinone (3)., Conclusion: The three compounds are new 1,4-benzoquinone derivatives.

Objective: To study the chemical constituents from the roots of Ardisia punctata., Method: Compounds were isolated by chromatographic techniques on silica gel and Rp-HPLC column. Their structures were elucidated by chemical and spectroscopic methods., Result: Twelve compounds were identified as 3-hydroxy-5-tridecyl-methyl phenyl ether (1), 5-pentadecyl-1, 3-benzenediol (2), 2-methoxy-6-tridecyl-1, 4-benzoquinone (3), 2-methoxy-6-pentadecyl-1, 4-benzoquinone (4), glutinol (5), ardisicrenoside A (6), ardisiacrispin B (7), 24-ethyl-5a-cholesta-7, 22(E)-dien-3-one (8), 24-ethyl-5alpha-cholesta-7, 22(E)-dien-3beta-ol (9), daucosterol (10), vanillin acid (11), tetratriacontanoic acid (12)., Conclusion: All the compounds were obtained from this plant for the first time.

Objective: To establish a method of the quantitative determination of acetylharpagide in Ajuga decumbens., Method: The chromatographic conditions were as follows: a Phenomenex Luna C18 column was used, the mobile phase was composed of acetontrile-water (15:85), the flow rate was 1.0 mL x min(-1) and the UV absorbance detection was set at 197 nm., Result: Linearity of acetylharpagide was in the range of 0.6-3.6 microg (r = 0.9993), and the average recovery and RSD were 99.13% and 2.48%, respectively., Conclusion: The contents of acetylharpagide ranged 0.40%-6.39% in A. decumbens. The method was simple, accurate and sensitive.

Objective: To study the chemical constituents from the roots of Ficus hirta., Method: Compounds were isolated by chromatographic techniques on silica gel and HP-20 resin columns. Their structures were elucidated by chemical and spectroscopic methods., Result: Ten compounds were identified as beta-sitosterol (1), stigmasterol (2), psoralene (3), 3beta-hydroxy-stigmast-5-en-7-one (4), 5-hydroxy-4', 6, 7, 8-tetramethoxy flavone (5), 4', 5, 6, 7, 8-pentamethoxy flavone (6), 4', 5, 7-trihydroxy-flavone (7), 3beta-acetoxy-beta-amyrin (8), 3beta-acetoxy-alpha-amyrin (9) and hesperidin (10)., Conclusion: The compounds 4, 5, 6 were obtained from this genus for the first time, and all the compounds were obtained from this plant for the first time.