Search

This study developed a new system for removing antibiotics using UV/ZIF-67 (Co)-activated peroxymonosulfate. The presence of antibiotic organic pollutants in urban sewage presents a substantial challenge for sewage treatment technologies. Due to the persistent chemical stability of antibiotics, their low environmental concentrations, and their resistance to degradation, effectively removing residual antibiotics remains a significant issue in urban wastewater treatment. This study introduces an eco-friendly photocatalytic technology designed to enhance the removal of oxytetracycline (OTC) from municipal wastewater using a UV/ZIF-67 (Co)/PMS system. The results showed that compared with UV, UV/PMS, ZIF-67 (Co), ZIF-67 (Co)/PMS, and UV/ZIF-67 (Co) systems, the UV/ZIF-67 (Co)/PMS system had the highest OTC removal rate. When 10 mg ZIF-67 (Co) and 1 mM PMS were applied to 100 mL 30 mg/L OTC solution, the degradation efficiency reached 87.73% under 400 W ultraviolet light. Increasing the dosage of ZIF-67 (Co) and PMS can improve the removal rate of OTC, but the marginal benefit of additional dosage is reduced. The highest degradation efficiency was observed at weakly acidic pH, which may be due to potential damage to the internal structure of the catalyst and reduced performance under extreme pH conditions. The influence of chloride ions and nitrate ions on the reaction system is minimal, while bicarbonate ions exhibit a significant inhibitory effect on the removal of OTC. The UV/ZIF-67 (Co)/PMS system exhibits adaptability to various water sources, including tap water, Guitang River water, and pure water. The results of free radical identification indicate the presence of hydroxyl and sulfate groups in the UV/ZIF-67 (Co)/PMS system, both of which play important roles in the degradation of OTC. This study offers valuable insights and technical support for the green, efficient, and environmentally friendly removal of antibiotics from urban wastewater. [ABSTRACT FROM AUTHOR]

Foodborne pathogenic bacteria have long been one of the food safety hazards in China. How to control effectively the proliferation of foodborne pathogenic bacteria in food has always been a hot topic. Based on the single factor experiments of plasma activated lactic acid (PALA) volume concentration, activation time and reaction time, taking Escherichia coli, Salmonella Enteritidis, Staphylococcus aureus and Listeria monocytogenes as the model strains, and the total number of colonies as the response value, the effects of the PALA on four foodborne pathogens were investigated in this study. The results showed that the killing rates of four foodborne pathogens increased with an increase of the PALA volume concentration, extension of activation time and prolongation of reaction time in certain ranges. When the PALA was activated for 120 seconds, the volume concentration was 0.2%, and the reaction between PALA and the four foodborne pathogens lasted for 10 minutes, about 7.71 lg CFU/mL of Escherichia coli, 4.52 lg CFU/mL of Salmonella, 4.03 lg CFU/mL of Staphylococcus aureus and 3.90 lg CFU/mL of Listeria monocytogenes in pure culture were killed. The killing rates of 4 kinds of the pure culture foodborne pathogens reached 99.9% (P<0.05), and more than 3.9 logarithm of the total number of colonies of pathogenic bacteria were killed. In summary, PALA can rapidly and efficiently kill common foodborne pathogens. [ABSTRACT FROM AUTHOR]

In order to reveal the approach and mechanism of soy protein self-assembly gel based on thymol nanocomplexation, the effects of protein concentration, thymol addition concentration, as well as initial and final pH value of the reaction on soy protein-thymol interaction and gel formation were investigated in the present study. The results showed that all the factors synergistically regulated the formation of soy protein-thymol nanocomplex gel. A higher thymol loading amount facilitated the formation of soy protein gel with a lower critical protein concentration (75 mg/mL). Additionally, the pH value adjusted to neutral at the end of complexation was necessary for soy protein-thymol nanocomplex gel formation. Considering that the average particle size and light scattering intensity of particles, as well as Th T fluorescence intensity of soy protein were increased by 26.70%, 154.67% and 93.78%, respectively at a pH of 7.0, the soy protein gel formation could have been largely associated with the fibrous aggregation that occurred in the soy protein after thymol nanocomplexation. The solubility of prepared gel in urea and DTT was increased, thus it is assumed that the intermolecular interaction forces that maintain the soy protein gel network were mainly hydrogen bonding, hydrophobic interactions, and disulfide bonding. Thus, the findings are important for developing cold-set soy protein gels and utilizing thymol. [ABSTRACT FROM AUTHOR]

Tender bamboo shoots undergo rapid senescence that influences their quality and commercial value after harvest. In this study, the tender sweet bamboo shoots ('Wensun') were packed by a passive modified atmosphere packaging (PMAP) to inhibit the senescence process, taking polyethylene package as control. The increase in CO 2 and the decrease in O 2 gas concentrations in the headspace atmosphere of the packages were remarkably modified by PMAP treatments. The modified gas atmosphere packaging inhibited the changes in firmness, as well as the content of cellulose, total pectin, and lignin in the cell walls of bamboo shoots. The enzymatic activities of cellulase, pectinase, and polygalacturonase that act on cell wall polysaccharides, and phenylalanine ammonia lyase, cinnamyl alcohol dehydrogenase, peroxidase, and laccase regulating the lignin biosynthesis were modified by PMAP treatment different from control during storage. The expression levels of the lignin biosynthesis genes PePAL3/4 , PeCAD , Pe4CL5, PeC4H, PeCCOAOMT, PeCOMT , cellulose synthase PeCESA1 , and related transcription factors PeSND2, PeKNAT7, PeMYB20, PeMYB63 , and PeMYB85 were clearly regulated. These results suggest that PMAP efficiently retards the changes in lignin and cell wall polysaccharides, thus delaying the senescence of tender sweet bamboo shoots during storage., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wang, Liu, Luo, Chen, Qi, Ye, Chen and Dai.)

The integrative bioplatform for capture, detection and release of circulating tumor cells (CTCs) is of great significance in clinical diagnosis and biomedical research. To fulfill this demand, we introduced a near-infrared (NIR) light-switched bioplatform for efficient isolation and downstream analysis of CTCs. The platform was created by first modifying the PEG-MoS 2 nanoflakes (NFs)@gelatin nanocomposite on the ITO surface, and then introducing the MUC1 aptamer as a specific recognition element via coupling reaction between aptamer and gelatin to achieve the specific capture for CTCs. Subsequently, the captured cells are released under a NIR light irradiation (808 nm) by using MoS 2 NFs as the NIR-regulated control element. Significantly, this platform could capture and release of CTCs with an excellent capture/release efficiency of 89.5% and 92.5%, respectively. Furthermore, the electrochemical bioplatform exhibited a wide linear range for the detection of CTCs from 50 to 1 × 10 6 cells mL -1 with a detection limit of 15 cells mL -1 . After 5 days of reculture, the released cells still maintain good cell shape and proliferation capacity. Moreover, the bioplatfrom is a simple, versatile, and universal system for the recognition, capture, release, and detection of different types of CTCs. Therefore, this bioplatform shows potential applications on the early diagnosis of cancers.

Herein, a ratiometric fluorescent method was developed for alkaline phosphatase (ALP) detection based on near-infrared (NIR) Ag 2 S quantum dots (QDs) and calcein through the competitive approach. The system based on Ag 2 S QDs and calcein shows green (maximum emission at 512 nm from calcein) and near infrared (NIR) fluorescence (maximum 798 nm from Ag 2 S QDs) under the same excitation wavelength (468 nm). In the presence of Ce 3+ , the fluorescence intensity of calcein is decreased due to static quenching, while the fluorescence intensity of Ag 2 S QDs is enhanced through aggregation induced emission (AIE). The p-nitrophenyl phosphate is hydrolyzed by ALP, and the yield phosphate ions bind with Ce 3+ with higher affinity than these of Ag 2 S QDs and calcein. Therefore, the green fluorescence from calcein is recovered while NIR fluorescence from Ag 2 S QDs is decreased. On the basis of these findings, a ratiometric fluorescence assay was developed for the measurement of ALP activity. The ratio of fluorescence intensity at 512 and 798 nm (F 512 /F 798 ) was well associated with the ALP concentration ranging from 2 to 100 mU/mL with the detection limit of 1.28 mU/mL. The method was successfully applied for detecting ALP in human serum with an acceptable recovery and bioimaging intracellular ALP with good performance. In addition, the approach was also employed for the screening ALP inhibitor., (Copyright © 2019 Elsevier B.V. All rights reserved.)

A luminescence resonance energy transfer (LRET) system was successfully developed using near-infrared (NIR) Ag 2 S nanodots (NDs) as the energy acceptors and upconversion nanoparticles (UCNPs) as the energy donors. The system possessing the properties of NIR excitation (980 nm) and NIR emission (795 nm) was used for the ratiometric detection and bioimaging of pH in tumor cells and zebrafish. Glutathione and mercaptopropionic acid (MPA) co-modified Ag 2 S NDs (GM-Ag 2 S NDs) were prepared by ligand exchange with an excellent pH-responsive property over a pH range of 4.0 to 9.0. The NIR GM-Ag 2 S NDs were covalently grafted with silica coated UCNPs, and an efficient LRET platform was developed via modulation of the thickness of the silica coating. Due to the LRET process between UCNPs and GM-Ag 2 S NDs, a ratiometric luminescence nanoprobe with the properties of NIR excitation-NIR emission was constructed for pH biosensing and bioimaging. On the basis of high contrast bioimaging, the nanoplatform can distinguish between tumor and normal tissue in the zebrafish model.

This paper reports a method that simultaneously detects three food-borne pathogenic bacteria, Salmonella typhimurium, Shigella flexneri, and Escherichia coli O157:H7, via an approach that combines magnetic microparticles for the enrichment and antibody-conjugated semiconductor quantum dots (QDs) as fluorescence markers. Using the water-in-oil reverse microemulsions method, the gamma-Fe(2)O(3) magnetic nanoparticles were coated with silica to empower the particles with high dispersibility and broad compatibility to biomacromolecules. The magnetic beads were then modified with amino silane, which could immobilize antibodies by glutaraldehyde treatment. The immunized magnetic beads and pathogenic bacteria formed "bead-cell" complexes in the enrichment procedure. QDs with different emission wavelengths (620, 560, and 520 nm) were immobilized with anti-S. typhimurium antibody, anti-S. flexneri antibody, and anti-E. coli O157:H7 antibody, respectively. Fluorescence microscope images and the fluorescence intensity of QDs labeled "sandwich" complexes (conjungated with antibodies against S. typhimurium, S. flexneri, and E. coli O157:H7, respectively) demonstrated that antibody-conjugated QDs could attach to the surface of bacterial cells selectively and specifically. In our method, we could detect food-borne pathogen bacteria in a food matrix at 10(-3) cfu/mL. We determined that a high concentration of proteins in food matrix would decrease the sensitivity of this method. This method, of which the detection procedures are completed within 2 h, can be applied to the rapid and cost-effective monitoring of bacterial contamination in food samples.