Preparation and Evaluation of Self-Assembled Porous Microspheres–Fibers for Removal of Bisphenol A from Aqueous Solution

A novel design of PP-<i>g</i>-DMAEMA/PM composite fiber as an efficient adsorbent was demonstrated by combining graft polymerization of dimethylaminoethyl methacrylate (DMAEMA) with self-assembled modification of porous microspheres (PMs) on the surface of polypropylene (PP) fiber. The structure and composition of the adsorbent was characterized by BET, XPS, FTIR, DSC, FESEM, and water angle. The kinetics and isotherm data indicated that the adsorption of bisphenol A (BPA) could be well-fitted by a pseudo-second-order kinetic model and the Langmuir isotherm, respectively. The thermodynamic studies indicated that the adsorption reaction was a spontaneous and exothermic process. Because of the π–π interactions and hydrogen bonds between BPA and PP-<i>g</i>-DMAEMA/PM, the resulting fiber obtained a higher adsorption amount (44.43 mg/g) of BPA. The presence of NaCl in the solution could facilitate the adsorption process, whereas the strong acid or strong alkali conditions and higher temperature of the solution were unfavorable. Besides, the obtained fiber reusability without obvious deterioration in performance was demonstrated by at least seven repeated cycles

Table_1_The inhibitory potential of green manure return on the germination and seedling growth of Eleusine indica L..docx

Trifolium repens L. (white clover) and Lolium perenne L. (ryegrass) are green manures widely used in conservation tillage systems worldwide. Eleusine indica L. (goosegrass) is a globally recognized noxious weed. Herein, we investigated the effects of aqueous extracts, decomposed liquids, and different straw-to-soil ratios on the germination and growth of goosegrass. The results showed that high concentrations (≥ 30%) of aqueous extracts or decomposed liquids of both green manures significantly inhibited germination-related parameters of goosegrass. The strongest inhibitory effect was observed for the 7-day decomposition treatment, and white clover’s inhibitory effect was greater than ryegrass’s. A pot experiment showed that non-photochemical quenching, catalase, and peroxidase activity levels of goosegrass leaves were significantly increased. At the same time, the net photosynthetic rate significantly decreased. Seedling growth was inhibited when the straw-to-soil ratio was greater than 3:100. The ryegrass treatments inhibited goosegrass seedlings more than the white clover treatments. This study demonstrated the inhibitory potential of white clover and ryegrass straw return on seed germination and seedling growth of goosegrass. The study has also helped to identify weed-resistant substances in these green manures so that their weed-control properties can be used more effectively and herbicide usage can be reduced.</p

Remote Activation of a Nanopore for High-Performance Genetic Detection Using a pH Taxis-Mimicking Mechanism

Aerolysin protein pore has been widely used for sensing peptides and proteins. However, only a few groups explored this nanopore for nucleic acids detection. The challenge is the extremely low capture efficiency for nucleic acids (>10 bases), which severely lowers the sensitivity of an aerolysin-based genetic biosensor. Here we reported a simple and easy-to-operate approach to noncovalently transform aerolysin into a highly nucleic acids-sensitive nanopore. Through a remote pH-modulation mechanism, we simply lower the pH on one side of the pore, then aerolysin is immediately “activated” and enabled to capture target DNA/RNA efficiently from the opposite side of the pore. This mechanism also decelerates DNA translocation, a desired property for sequencing and gene detection, allowing temporal separation of DNAs in different lengths. This method provides insight into the nanopore engineering for biosensing, making aerolysin applicable in genetic and epigenetic detections of long nucleic acids

Hydrogel formation and stability.

<p>Optical images of three resulting hydrogels formed by 2.0 wt% of 4-armed-PEG-Mal and 2.0 wt% of the corresponding protein. A, TIP1 4C gel; B, TIP1 2C gel; and C, TIP1 2C RGD gel. Both TIP1 2C gel and TIP1 2C RGD gel remained transparent after 24 hours.</p

A Genetically Modified Protein-Based Hydrogel for 3D Culture of AD293 Cells

<div><p>Hydrogels have strong application prospects for drug delivery, tissue engineering and cell therapy because of their excellent biocompatibility and abundant availability as scaffolds for drugs and cells. In this study, we created hybrid hydrogels based on a genetically modified tax interactive protein-1 (TIP1) by introducing two or four cysteine residues in the primary structure of TIP1. The introduced cysteine residues were crosslinked with a four-armed poly (ethylene glycol) having their arm ends capped with maleimide residues (4-armed-PEG-Mal) to form hydrogels. In one form of the genetically modification, we incorporated a peptide sequence ‘GRGDSP’ to introduce bioactivity to the protein, and the resultant hydrogel could provide an excellent environment for a three dimensional cell culture of AD293 cells. The AD293 cells continued to divide and displayed a polyhedron or spindle-shape during the 3-day culture period. Besides, AD293 cells could be easily separated from the cell-gel constructs for future large-scale culture after being cultured for 3 days and treating hydrogel with trypsinase. This work significantly expands the toolbox of recombinant proteins for hydrogel formation, and we believe that our hydrogel will be of considerable interest to those working in cell therapy and controlled drug delivery.</p></div

A schematic diagram of hydrogel formation.

<p>The Michael addition between maleimides of 4-armed-PEG-Mal and thiols in each mutant protein leads to the formation of 3D networks for hydrogelations. The blue balls represent TIP1 protein. The yellow balls represent amino acids that were replaced by cysteine in TIP1. The pink lines represent 4-armed-PEG-Mal.</p

Hydrogel characterization.

<p>A, A rheological measurement in dynamic frequency sweep mode at the strain of 1% for each gel containing 2.0 wt% of 4-armed-PEG-Mal and 2.0 wt% of the protein. Closed symbols: elasticity (G’) values and open symbols: viscosity (G”) values. Circles: TIP1 2C gel and triangles: TIP1 2C RGD gel. B, An SEM image of the TIP1 2C gel. C, An SEM image of the TIP1 2C RGD gel.</p

Determining cell viability.

<p>A live-dead assay of AD293 cells cultured in TIP1 2C RGD (top) and TIP1 2C (down) hydrogels at different time points. A and D, day 1; B and E, day 2; and C and F, day 3. Live cells were stained green and dead cells were stained red. Magnification: 20×.</p

DataSheet_1_Weed suppression and antioxidant activity of Astragalus sinicus L. decomposition leachates.docx

Astragalus sinicus L. (milk vetch), a versatile plant that has a soil-enriching effect as green manure, is widely planted in the temperate zone of China. In previous experiments, milk vetch incorporated into the soil as green manure showed potential for goosegrass control. However, “what exactly happens at the chemical level?” and “what are the compounds that are potentially responsible for the phytotoxic effects observed during those previous assays?” In a recent study, in vitro phytotoxicity bioassays and chemical analyses of milk vetch decomposition leachates were carried out to explore the relationship between the temporal phytotoxic effects and the dynamics of chemical composition. For that, milk vetch decomposition leachates with a decay time of 12 h, 9 days, 12 days, 15 days, and 18 days were analyzed for organic compounds by liquid chromatography. The main results were as follows: (1) three compounds with goosegrass suppression potential produced during the decomposed process, i.e., 4-ethylphenol, N-acrylimorpholine, and allyl isothiocyanate. 2-Hydroxyethyl acrylate was present in the 12-h decomposition leachates but was at its highest concentration of 127.1 µg ml−1 at 15 days. (2) The cultures were configured according to the four concentrations of goosegrass-resistant active substances measured in the 15-day decomposition leachate and, as with the 15-day decomposition leachate, the mixture cultures inhibited 100% of goosegrass germination at the high concentrations (≥ 30%), which suggests that these substances have goosegrass suppression potential. (3) The high total phenolic content (302.8–532.3 mg L−1), the total flavonoid content (8.4–72.1 mg L−1), and the reducing activity of the decomposition leachates for different decay times may explain why the incorporation of milk vetch into the soil did not lead to peroxidation of goosegrass in the previous study. (4) Finally, the changes in acid fraction and total content (1.9–4.2 mg ml−1) for different decay times explain the variations in pH of the decomposition leachates, which, when discussed in conjunction with previous studies, may lead to changes in soil nutrient effectiveness and consequently affect crop growth. This study can provide a reference for green weed control research.</p

The purification of TIP1 2C.

<p>The size-exclusion chromatography of TIP1 2C was performed in a Superose 12 10/300 at two concentrations. Inset: A 20% SDS-PAGE gel result for each fraction.</p