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The efficient synthesis of myofibrillar protein(MRN)-gallic acid (GAD) complex in ultrasound (UID)-assisted processing is a challenging problem in food manufacturing. In this investigation, the effect of viscosity characteristics on the efficiency of UID processing in MRN-based beverages was analyzed. Both viscosity and surface tension can increase sono-physico-chemical effects on the degradation of terephthalic acid and crystal violet, with surface tension having a more significant effect (negative correlation, R2 = 0.99) than viscosity (positive correlation, R2 = 0.79). The structural indicators and microstructure demonstrated that the reaggregation and refolding of the MRN structure during the modification procedure occurred with relatively small three-dimensional dimensions. Compared to the MRN/GAD4 group, the water contact angle of the MRN/GAD7 system enhanced by 129.44%, leading to greater system stability. The ABTS-scavenging capacity of the system increased by approximately 19.45% due to the increase in viscosity of these two categories.

Our aim was to assess the blood physiology and antioxidant and immune responses of the olive flounder (Paralichthys olivaceus) following pH changes in the water. P. olivaceus (mean weight 95.7 ± 6.5 g and mean length 21.4 ± 1.3 cm) were exposed to the different pH levels (pH 5, 6, 7, 8, 9, and 10) for 2 weeks. Blood physiology parameters, such as the levels of hematocrit, magnesium, glucose, glutamic oxalate transaminase (GOT), glutamic pyruvate transaminase (GPT), and alkaline phosphatase (ALP) were significantly altered by low (acidic) pH or high (alkaline) pHs. With regard to antioxidant responses, the superoxide dismutase (SOD) and glutathione S-transferase (GST) activities in the liver were significantly altered by the pH changes, but there were no significant changes of these activities in the gill tissues. The immunoglobulin M levels increased significantly at pH 10 after 2 weeks. The results of this study suggest that pH changes (acidity: < pH 6, alkalinity:> pH 9) affect blood physiology, as well as antioxidant and immune responses in P. olivaceus.

In this study, experiments were designed to reveal in-depth information of the effect of pH and hydraulic retention time (HRT) on biohydrogen fermentation from liquid swine manure supplemented with glucose using an Anaerobic Sequencing Batch Reactor (ASBR) System. Five values of HRT (8, 12, 16, 20, and 24 h) were first tested and the best HRT determined was further studied at five pH levels (4.4, 4.7, 5.0, 5.3, and 5.6). The results showed that for HRT 24 h, there was a dividing H2 content (around 37%) related to the total biogas production rate for the ASBR System running at pH 5.0. When the H2 content went beyond 37%, an appreciable decline in biogas production rate was observed, implying that there might exist an H2 content limit in the biogas. For other HRTs (8 through 20 h), an average H2 content of 42% could be achieved. In the second experiment (HRT 12 h), the highest H2 content (35%) in the biogas was found to be associated with pH 5.0. The upswing of pH from 5.0 to 5.6 had a significantly more impact on biogas H2 content than the downswing of pH from 5.0 to 4.3. The results also indicated good linear relationships of biogas and H2 production rates with HRT (r=0.9971 and 0.9967, respectively). Since the optimal ASBR operating conditions were different for the biogas/H2 production rates and the H2 yield, a compromised combination of the running parameters was determined to be HRT 12 h and pH 5.0 in order to achieve good biogas/H2 productions.

Dissolution of the exposed sphalerite (marmatite) in abandoned mining sites and tailings may exacerbate acid and metalliferous drainage (AMD) hazards. Cupric ions are inevitable ions in AMD systems but its action mechanism on the dissolution of sphalerite is still unclear. In this work, the possible phase transition from sphalerite to chalcopyrite is firstly discovered in acidic cupric ions solution according to the results of Raman and (synchrotron radiation-based) X-ray (micro-) diffractometer spectra, which should be an important reason that mediates the dissolution of sphalerite. Results of DFT calculations reveal the underlying mechanism that Cu 2+ can selectively replace zinc in marmatite lattices and further diffuse into the matrix. Additionally, a strong correlation between the cupric ion consumption with the pH value variation is discussed and the effects of the formed new phase on the dissolution kinetics of marmatite were researched. According to this work, the action mechanism of cupric ions on sphalerite dissolution in acidic environments is furtherly clarified., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Polyglycolic acid (PGA) is a faster biodegradable polymer for various implants, frequently causing different macrophages' activation. In this study, we undertook a comparable study of PGA's degradation on macrophages' activation with different PGA crystallinity (in porous and fibrous 3D scaffolding format) in an in vitro and in vivo model. The incubation medium containing PGA degradation products, with different pH value of 7.1, 6.1 and 3.6, was added to RAW 264.7 macrophages' culture to simulate different degradation phases. The addition of hydrochloric acid with the same pH values in the culture media was used to compare and simplify the acid types' effect on macrophages. The scaffolds were implanted to mouse subcutaneously for 6 weeks. To correlate the degradation rate between the in vitro and in vivo models, PGA scaffolds were grafted by rhodamine-b covalently enabling the detection of PGA degradation through fluorescence intensity decay. It was confirmed that porous PGA degraded faster than fibrous scaffolds due to lower crystallinity. The acidic PGA degradation products (GA) did not promote IL-10 production, but inhibited IL-1β, IL-6 and TNF-α production in 7-days' culture significantly. The use of HCl with the same pH value as PGA degradation products in culture did not produce the same inhibition effect as GA. The mouse model showed that the degradation of PGA scaffolds was accelerated in vivo in the first two weeks, mainly due to tissue ingrowth. The fast degradation of porous scaffolds triggered M1 macrophages into the implantation site, whilst the slow degradation of PGA fibers promoted the polarization of macrophages into M2 pro-healing phenotypes. This study provides a good foundation to study and design biodegradable biomaterials toward immunomodulation., Competing Interests: Declaration of competing interest The authors declare no competing financial interest., (Copyright © 2019. Published by Elsevier B.V.)

Good hemocompatibility and cell compatibility are essential requirements for coronary stents, especially for biodegradable magnesium alloy stents, which could change the in situ environment after implanted. In this work, the effects of magnesium ion concentration and pH value on the hemolysis and cytotoxicity have been evaluated. Solution with different Mg(2+) concentration gradients and pH values of normal saline and cell culture media DMEM adjusted by MgCl2 and NaOH respectively were tested for the hemolysis and cell viability. Results show that even when the concentration of Mg(2+) reaches 1000 μg/mL, it has little destructive effect on erythrocyte, and the high pH value over 11 caused by the degradation is the real reason for the high hemolysis ratio. Low concentrations of Mg(2+) (<100 μg/mL) cause no cytotoxicity to L929 cells, of which the cell viability is above 80%, while high concentrations of Mg(2+) (>300 μg/mL) could induce obvious death of the L929 cells. The pH of the extract plays a synergetic effect on cytotoxicity, due to the buffer action of the cell culture medium. To validate this conclusion, commercial pure Mg using normal saline and PBS as extract was tested with the measurement of pH and Mg(2+) concentration. Pure Mg leads to a higher hemolysis ratio in normal saline (47.76%) than in buffered solution (4.38%) with different pH values and low concentration of Mg(2+). The Mg extract culture media caused no cytotoxicity, with pH=8.44 and 47.80 μg/mL Mg(2+). It is suggested that buffered solution and dynamic condition should be adopted in the hemolysis evaluation., (Copyright © 2014. Published by Elsevier B.V.)