DETERMINATION OF CATECHINS IN TEA BY MICELLAR ELECTROKINETIC CHROMATOGRAPHY WITH A GRAPHENE OXIDE-COATED CAPILLARY

<div><p>A novel approach was developed for the determination of four catechins, (-)-epigallocatechin gallate, (-)-epigallocatechin, (-)-gallocatechin gallate, and (-)-epicatechin, in tea by micellar electrokinetic chromatography (MEKC) using an acidic phosphate buffer (40 mM, 100 mM sodium dodecyl sulfate, and 30% methanol, pH 3.0). The linear dynamic ranges for the catechins were between 25 and 250 μg/mL, and the graphene oxide-coated capillary offered satisfactory accuracy, precision, and limits of detection. The developed method was employed for the determination of catechins in tea.</p> </div

The original gel images.

(DOCX)</p

Multiplexed PCR verification of the dominantly grown tobacco seedlings under Phi irrigation in the weed control simulation test.

The blue-circled bigger seedlings in Fig 6 were substantiated as transgenic tobaccos by genomic PCR with three primer-pairs EcBAP-5Bm/EcBAP-3Sc, EcBAP-5Bm/NosDw-Rv, and 35sPro-Fw/EcBAP-3Sc. Arrow-heads indicate the target PCR bands. The original gel image of this figure is available in S1 File. (TIF)</p

Generation of EcBAP(Kan) transgenic tobacco plants by Kan selection.

(A) The procedure of tobacco transformation of plant vector pET(EcBAP) via Agrobacterium infiltration and Kan selection. (B) Identification of Kan-resistant EcBAP transgenic tobacco plantlets by multiplexed PCR with three primer-pairs EcBAP-5Bm/EcBAP-3Sc, EcBAP-5Bm/NosDw-Rv, and 35sPro-Fw/EcBAP-3Sc. M: DNA marker; Arrow-heads indicate the target PCR bands. The original gel image of this figure (B) is available in S1 File. (TIF)</p

RT-PCR analysis of <i>EcBAP</i> expression in the tissues of root, stem, and leaf of EcBAP(Phi) transgenic tobacco plants.

(A) The extracted total RNA; (B) RT-PCR of 18S rRNA (the internal reference gene) with a correct product (552 bp) by primer-pair Nt18S-iFw/Nt18S-iRv; (C) RT-PCR of EcBAP with a correct product (408 bp) by primer-pair EcBAP-iFw/EcBAP-iRv. R: root; S: stem; L: leaf; Arrow-heads indicate the target PCR bands. The original gel images of this figure (A–C) are available in S1 File. (TIF)</p

The framework diagram of this study.

(TIF)</p

Leaf explant regeneration test of EcBAP(Kan) transgenic tobacco under high Phi stress.

Small leaf pieces (0.5 cm × 0.5 cm) of WT and EcBAP(Kan) transgenic tobacco were pairwise laid on (A) MS (-Pi) or (B) standard MS medium, containing Phi of high concentrations (4, 5, 10 mM). After 7 days, 1 month, and even 2 months, the differentiation/regeneration status of these leaf explants under Phi stress were photo-recorded and compared between WT and EcBAP(Kan) transgenic tobacco. (TIF)</p

The Agrobacterium-infiltrated tobacco transformation of plant vector pET(EcBAP) under Phi selection.

Experiments were performed on (A) standard MS medium and (B) MS (Pi-) medium without Pi supply.</p

Facile Synthesis of Hierarchically Structured Magnetic MnO₂/ZnFe₂O₄ Hybrid Materials and Their Performance in Heterogeneous Activation of Peroxymonosulfate

In heterogeneous catalysis for water treatment, feasible recovery of nanocatalysts is crucial to make the process cost-effective and environmentally benign. In this study, we applied two strategies, for example, magnetic separation and hierarchical structure of solid catalysts, to ensure manganese catalysts are readily separable, meanwhile their catalytic performance was retained by the nanosized structure of MnO2 nanosheets or nanorods. ZnFe2O4 was used as the magnetic core and MnO2 corolla-like sphere consisting of nanosheets, and sea-urchin shaped structure made of nanorods, were fabricated by a hydrothermal method at 100 and 140 °C, respectively. Crystalline structure, morphology and textural property of the materials were investigated. The prepared catalysts were able to effectively activate peroxymonosulfate (PMS) to generate sulfate radicals for catalytic oxidation of a typical organic pollutant of phenol. After the heterogeneous catalysis, the catalysts were easily recovered by applying an external magnetic field. The effects of temperature and repeated use on the degradation efficiencies were evaluated. The generation and evolution of sulfate radicals and phenol oxidation were studied using both competitive radical tests and electron paramagnetic resonance (EPR)

The recombinant EcBAP has an apparent Phi-oxidizing activity <i>in vitro</i>.

(A) The recombinant EcBAP was analyzed by SDS-PAGE and coomassie blue staining for purity assessment; (B) The recombinant EcBAP at the non-denatured status was visualized by native-PAGE and coomassie blue staining; (C) The Phi-oxidizing activity of recombinant EcBAP was qualitatively evaluated by native-PAGE gel activity staining in a consecutive reactant system composed of Phi and methyl green; (D) Ten individual reactions (#1–#10) were conducted for Pi/AM/MG-based spectrometric assay to quantitatively determine the Phi-oxidizing activity of recombinant EcBAP, and (E) The calculated Phi-oxidizing activity (μg Pi · μg-1 EcBAP) of all ten reactions were shown together, with the mean (±SD) marked in red (also see S2 File). Arrow-head indicates the recombinant EcBAP protein. The original gel images for this figure (A–C) are available in S1 File.</p