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This paper investigated the influence of ultraviolet (UV) illumination on the corrosion behavior of 7A04 aluminum alloy in 3.5% NaCl solutions with various pH values (pH=5.0, 7.0, and 10.0) using weight loss measurement, electrochemical methods, and surface analysis techniques. The research results indicated that the corrosion products of 7A04 alloy in salt solutions with different pH values all exhibited n-type semiconductor properties and could trigger the photovoltaic effect under UV illumination. Simultaneously, UV illumination reduced the compactness of the corrosion products, inhibited the enrichment of copper compounds (Cu2O), and promoted the generation of hydroxyl radicals in the solution. Therefore, UV illumination significantly accelerated the corrosion process of 7A04 alloy, with the overall acceleration effect ranking as follows: alkaline > neutral > acidic. In addition, the corrosion mechanism of 7A04 alloy in the test solutions with and without UV illumination was also discussed in this paper.

Background: The association between pH values and outcome for patients after out-of-hospital cardiac arrest (OHCA) was not fully elucidated; besides, the relationship of change in pH values and neurological outcome was unknown. The aim was to explore the association of pH values as well as change in pH values and neurological outcome for OHCA cardiac patients. Methods: The adult patients with non-traumatic out-of-hospital cardiac arrest, shock-refractory ventricular fibrillation or pulseless ventricular tachycardia, and at least two arterial blood gases analysis recorded after admission were included. The change in pH values is calculated as the difference between the second and first pH value, and divided by time interval got the rate of change in pH values. The primary outcome was modified Rankin Score (mRS), dichotomized to good (mRS 0–3) and poor (mRS 4–6) outcomes at hospital discharge. The independent relationship of the first pH value, second pH value, and changes in pH values with neurological outcome was investigated with multivariable logistic regression models, respectively. Results: A total of 1388 adult patients were included for analysis, of which 514 (37%) had good neurological outcome. The median first pH value and second pH value after admission were 7.21 (interquartile range [IQR] 7.09–7.29) and 7.28 (IQR 7.20–7.36), respectively. The median absolute, relative change, and rate of changes in pH values were 0.08 (IQR 0.01–0.16), 1.10% (IQR 0.11–2.22%), and 0.02 (IQR 0–0.06) per hour, respectively. After adjusting for confounders, the higher first pH value (odds ratio [OR] 3.81, confidence interval [CI] 1.60–9.24, P = 0.003) and higher second pH value (OR 9.54, CI 3.45–26.87, P < 0.001) after admission were associated with good neurological outcome, respectively. The absolute (OR 1.58, CI 0.58–4.30, P = 0.368) and relative (OR 1.03, CI 0.96–1.11, P = 0.399) change as well as the rate of change (OR 0.98, CI 0.33–2.71, P = 974) in pH values were not associated with neurological outcome. Conclusions: For OHCA patients, abnormality in pH values was very common, with a more acidic pH value indicating poor neurological outcome. However, the change in pH values was not associated with outcomes.

The high alkaline condition of concrete naturally protects embedded steel bars from corrosion by forming a passive protective film. The pH of concrete is generally high, but concrete with different mix compositions may have various pH values. The pH of concrete may decrease over time due to long-term mechanical, chemical, biological and physical factors. Therefore, monitoring the pH value of concrete is crucial to checking if its alkalinity is within an acceptable range and ensuring that the concrete structure is in good health condition. However, the pH measurement for cement-based materials is not standardised. Ex-situ leaching, one of the recommended methods for pH measurement, is simple and practical. In this method, the sample will be crushed, leached and tested using a pH electrode probe. The lifespan of the pH electrode probe may decrease due to the existing suspended particles in the solution. Therefore, one recommendation is to filter the solution before using the probe. In this study, the effect of different filtering setups on the pH value of a cement mortar with a cement-to-sand ratio of 1:3 was evaluated. pH test results showed that filtering can produce similar outcomes to those without filtering, regardless of the type of filter paper and its pore size. However, filtering is strongly recommended for electrode protection of the pH meter. As an innovative filtering setup for cement-based materials, syringe filtering was introduced in this study because it is more economical and its operation is simpler compared to the other methods.

This study focuses on addressing the limitations associated with most chemical derivatization methods commonly used for formaldehyde detection. These methods often suffer from prolonged derivative times (≥30 min) and complex procedures, which hinder their ability to meet the requirements of real-time and accurate sensing. In this research, a novel formaldehyde indicator system based on hyperbranched polyamine molecule was developed, and its mechanism and principles of color change were investigated. The findings revealed that hyperbranched polyamine molecule effectively reacts with formaldehyde, leading to a reduction in electron cloud density in the amine group N and subsequently causing a decrease in pH value. This reaction enables the visualization of formaldehyde detection through changes in the indicator spectrum. Moreover, the spectral variation pattern exhibits a strong linear correlation with the formaldehyde concentration when the PAMAM concentration is optimized. The detection limit of this method was determined to be 1.8 ppm. Notably, the reaction between PAMAM and formaldehyde is almost instantaneous, the color change is insensitive to temperature, and the method demonstrates high selectivity. Overall, this research contributes to the advancement of real-time formaldehyde monitoring technology and provides insights for future developments in this field.

During the hydration of CA cement exists a dormant period, which is responsible for the setting kinetics of CA cement bonded refractory castables. The dormant period is believed to be caused by an Al–O–H passivation layer on the CA cement particles. Recent publications indicate that the dissolution (aging) of the passivation layer is closely connected to the prevailing pH value of the pore solution during setting. The higher the pH value, the faster the dissolution of the passivation layer.As phosphate additives, frequently used as dispersing agent, differ in their pH value when dissolved in water it is reasonable that they change the setting kinetics of CA cement bonded refractory castables. Commonly used sodium polyphosphate (S-PP, special case S-TPP for sodium tripolyphosphate) dispersing agents mainly differ in chain length, and therefore in Na+ and phosphate concentration, with different setting kinetics as a result.To investigate the influence of S-(T)PP on setting kinetics, sonic velocity and pH measurements were conducted on S-(T)PP/citric acid dispersed and CA cement bonded refractory castables during their setting. Different phosphates, differing in portion of Na+ to phosphate and medium chain length of the phosphate molecules, were used in varied concentrations within refractory castables to quantify the shift in setting kinetics and verify the role of the pH value during the hydration of CA cement.It was found that the chain length of the phosphate molecule of S-(T)PP influences the setting kinetics, and especially the length of the dormant period of the hydration of CA cement, in an indistinct way. Minor differences within the Na+ concentration at differing chain length S-(T)PP showed a comparable tendency to influence the hydration kinetics of CA cement as the chain length of the phosphate molecule was varied. However, an increase of the concentration of the applied S-(T)PP, which goes along with a distinctly increased Na+ concentration, resulted in a significant shorter dormant period and correspondingly an accelerated main hydration of CA cement. The corresponding pH value during the dormant period of the hydration of CA cement increased concurrently to the increase of the S-(T)PP and Na+ concentration.It is discussed that this increase of the pH value of the pore solution of the refractory castable results from an increase of the Na+ concentration from the S-(T)PP, while phosphate molecules are precipitated as Ca-phosphate. This indicates that the dissolution of the Al–O–H passivation layer accelerates with an increasing Na+ concentration (equivalent to increasing pH value) in the pore solution. Thereby, the dormant period is shorter and the hydration of CA cement starts earlier.The general tendency that additives of alkaline nature are accelerating the setting kinetics could be linked to the pH value during the dormant period. Therefore, the theory of the pH dependent aging of the Al–O–H passivation layer on CA cement particles was confirmed. As a directly applicable result, S-(T)PP may be used as accelerator (accelerating the CA cement hydration) beside their dispersing effect.

Pizza is a popular food consumed around the world every day. Hot food temperatures were obtained from 19,754 nonpizza samples and 1,336 pizza temperatures were taken from dining facilities operated by Rutgers University between 2001 and 2020. These data showed that pizza was more frequently out of temperature control than many other foods. A total of 57 pizza samples that were out of temperature control were collected for further study. Pizza was tested for total aerobic plate count (TPC), Staphylococcus aureus, Bacillus cereus, Lactic acid bacteria, coliforms, and Escherichia coli. Water activity of pizza and surface pH of each individual pizza component (topping, cheese, bread) were measured. Predictions for the growth of four relevant pathogens were made for select pH and water activity values using ComBase. Rutgers University dining hall data show only about 60% of all foods that are pizza are held at the appropriate temperature. When pizza contained detectable microorganisms (∼70% of samples), average TPC ranged from 2.72 log CFU/g to 3.34 log CFU/g. Two pizza samples contained detectable S. aureus (∼50 CFU/g). Two other samples contained B. cereus (∼50 and 100 CFU/g). Five pizza samples contained coliforms (4–9 MPN/g), and no E. coli were detected. Correlation coefficients (R2 values) for TPC and pickup temperature are quite low (

The acidity and alkalinity of aggregates greatly affect the stability, demulsification rate, and road performance of asphalt mixtures. To study the effect of acidity and alkalinity and chemical composition of aggregates, five aggregates, namely limestone (S1, S2, S3, S4) and basalt (X), were studied. The pH and alkalinity values of aggregates and their main chemical compositions (MgO, Al2O3, CaO, Fe2O3, and SiO2) were tested. The pH/alkalinity measured values and pH/alkalinity composite values of the aggregates were analyzed using grey correlation and principal component analyses. The findings indicated a strong correlation between the composite and measured values for aggregate acidity and alkalinity indexes (pH: 0.9105, alkalinity: 0.9241). Additionally, the principal component analysis demonstrated that the composite values were in good agreement with the measured values (pH: R2 = 0.746, alkalinity: R2 = 0.992), which corroborated the grey correlation and regression model results, confirming significant correlations. This result indicates that the pH/alkaline index of the chemical constituents of the aggregate can be used to characterize the pH/alkaline index of the aggregate. The relationship model between aggregate and their chemical constituent’s acid and alkaline indexes can provide a theoretical reference for the in-depth study of the application of aggregate acid and alkaline in road engineering.

The effect of pH value on the corrosion behavior and microstructural evolution of carbon fiber reinforced magnesium matrix (Cf/Mg) composites in NaCl solution were investigated. The results of the electrochemical test revealed that the corrosion current density of Cf/Mg composites in pH = 13 solution achieved 3.4 × 10−5 Am/cm2, which was one order and two orders of magnitude lower than that of pH = 7 solution (2.6 × 10−4 Am/cm2) and pH = 1 solution (1.1 × 10−3 Am/cm2), respectively. Electrochemical impedance spectroscopy (EIS) curves implied that the corrosion resistance of Cf/Mg composites was enhanced when the pH value increased. The microstructure of the Cf/Mg composites after corrosion in the solution with pH = 13 first appeared as some point-like bumps, and then gradually grew into a lamellar structure. The corrosion mechanisms and microstructural evolution of the Cf/Mg composites were systematically discussed.

The coupled system of column gel electrophoresis and inductively coupled plasma mass spectrometry (GE-ICP-MS) is a highly effective technique for detecting metal-binding proteins. However, it takes a long time for this method to test a single sample, which greatly limits its application. In this study, GE-ICP-MS system was optimized by adjusting the analytical conditions, including the concentration and pH of running buffer and the proportion of polyacrylamide gel. The results of the experiment showed that the migration speed of proteins in GE was enhanced by increasing the electrolyte concentration in the running buffer solution. Additionally, the ICP-MS response, which was dramatically decreased because of the change in running buffer solution, can be stabilized by adjusting pH of running buffer. Meanwhile, the optimization of polyacrylamide gel ratio allows GE-ICP-MS to maintain high resolution for proteins of similar molecular weight with increased detection speed. After increasing the concentration of running buffer by 10 times, four iodine labeled proteins were successfully separated at baseline by the GE-ICP-MS system at pH 8.0 in 40 min using a resolving gel (8%, 7 cm) and a stacking gel (4%, 1 cm), which was three times faster than the original one. Finally, the optimized method was proved by detecting a silver-binding protein in rat plasma samples. The above method provided an effective and rapid detection for metal-binding proteins in organism., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The way the pH falls post-slaughter has an impact on meat quality. Pork longissimus muscles (n=48) were sorted in fast- (FG) (n=15) and normal glycolysing (NG) (n=33) muscles according to the post-slaughter pH 45 min values (FG6.0). FG muscles (5.84±0.04) compared with NG muscles (6.27±0.04) were accompanied with higher temperature, electrical conductivity, lightness and yellowness, and reduced grill loss and shear force values (P

This study focuses on addressing the limitations associated with most chemical derivatization methods commonly used for formaldehyde detection. These methods often suffer from prolonged derivative times (≥30 min) and complex procedures, which hinder their ability to meet the requirements of real-time and accurate sensing. In this research, a novel formaldehyde indicator system based on hyperbranched polyamine molecule was developed, and its mechanism and principles of color change were investigated. The findings revealed that hyperbranched polyamine molecule effectively reacts with formaldehyde, leading to a reduction in electron cloud density in the amine group N and subsequently causing a decrease in pH value. This reaction enables the visualization of formaldehyde detection through changes in the indicator spectrum. Moreover, the spectral variation pattern exhibits a strong linear correlation with the formaldehyde concentration when the PAMAM concentration is optimized. The detection limit of this method was determined to be 1.8 ppm. Notably, the reaction between PAMAM and formaldehyde is almost instantaneous, the color change is insensitive to temperature, and the method demonstrates high selectivity. Overall, this research contributes to the advancement of real-time formaldehyde monitoring technology and provides insights for future developments in this field., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Inc.)

Pizza is a popular food consumed around the world every day. Hot food temperatures were obtained from 19,754 nonpizza samples and 1,336 pizza temperatures were taken from dining facilities operated by Rutgers University between 2001 and 2020. These data showed that pizza was more frequently out of temperature control than many other foods. A total of 57 pizza samples that were out of temperature control were collected for further study. Pizza was tested for total aerobic plate count (TPC), Staphylococcus aureus, Bacillus cereus, Lactic acid bacteria, coliforms, and Escherichia coli. Water activity of pizza and surface pH of each individual pizza component (topping, cheese, bread) were measured. Predictions for the growth of four relevant pathogens were made for select pH and water activity values using ComBase. Rutgers University dining hall data show only about 60% of all foods that are pizza are held at the appropriate temperature. When pizza contained detectable microorganisms (∼70% of samples), average TPC ranged from 2.72 log CFU/g to 3.34 log CFU/g. Two pizza samples contained detectable S. aureus (∼50 CFU/g). Two other samples contained B. cereus (∼50 and 100 CFU/g). Five pizza samples contained coliforms (4-9 MPN/g), and no E. coli were detected. Correlation coefficients (R 2 values) for TPC and pickup temperature are quite low (<0.06). Based on the pH and water activity measurements, most (but not all) of the pizza samples would be considered to potentially require time temperature control for safety. The modeling analysis shows that the organism most likely to pose a risk would be S. aureus, and the largest magnitude increase predicted is 0.89 log CFU at 30°C, pH 5.52, and water activity 0.963. The overall conclusion from this study is that while pizza represents a theoretical risk, the actual risk would likely only manifest for pizza samples that are held out of temperature control for time periods of more than eight hours., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

The mechanism of removing antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARGs) by persulfate was attributed to the generation of reactive oxygen species (ROS). However, the potential contribution of decreased pH in persulfate system to ARB and ARGs removal has rarely been reported. Here, the efficiency and mechanism of removing ARB and ARGs by nanoscale zero-valent iron activated persulfate (nZVI/PS) were investigated. Results showed that the ARB (2 × 10 8 CFU/mL) could be completely inactivated within 5 min, and the removal efficiencies of sul1 and intI1 were 98.95% and 99.64% by nZVI/20 mM PS, respectively. Investigation of mechanism revealed that hydroxyl radicals was the dominant ROS of nZVI/PS in removing ARB and ARGs. Importantly, the pH of nZVI/PS system was greatly decreased, even to 2.9 in nZVI/20 mM PS system. Impressively, when the pH of the bacterial suspension was adjusted to 2.9, the removal efficiency of ARB, sul1 and intI1 were 60.33%, 73.76% and 71.51% within 30 min, respectively. Further excitation-emission-matrix analysis confirmed that decreased pH contributed to ARB damage. The above results on the effect of pH indicated that the decreased pH of nZVI/PS system also made an important contribution for the removal of ARB and ARGs., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

In this work, the influence of soy protein isolated at different pH values (1-9) on the self-assembly behaviors of bacterial cellulose nanofibers/soy protein isolate (BCNs/SPI) colloidal particles via anti-solvent precipitation were investigated. The results showed that the formation of BCNs/SPI at pH values of 1-5 was mainly driven by electrostatic interaction, while the formation of those at pH values of 5-9 was driven by weak molecular interactions including hydrogen bonding and steric-hindrance effect. The FTIR demonstrated that the conformation of protein involved a transition from order to disorder at the level of secondary structure as pH values were away from the isoelectric point. The fluorescence spectroscopy and UV-vis adsorption spectroscopy indicated that hydrophobic region of SPI at pH value of 5 displayed more exposed as compared with that at pH values away from the isoelectric point. The changes in structure conformation of SPI induced by pH values led to the changes in properties of the BCNs/SPI colloidal particles including particle size, microstructure, crystallinity, hydrophily, thermal stability, and rheological properties. Furthermore, the structures of BCNs/SPI colloidal particles at different pH values significantly affected the stability of Pickering emulsion gels stabilized by the corresponding complex colloidal particles. This study provided a theoretical basis for the design of food-grade Pickering emulsion gels stabilized by BCNs/SPI complex colloidal particles., Competing Interests: Declaration of competing interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in, or the review of, the manuscript entitled, “Characterization of bacterial cellulose nanofibers/soy protein isolate complex particles for Pickering emulsion gels: the effect of protein structure changes induced by pH”., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Owing to the toxicity and difficulty in degradation, how to the effective separation for the residual dyes in the aqueous solution is still an issue with great challenge in the area of environmental protection. Now, to high-efficiency removal of organic dyes from the aqueous solution, we design a unique AlOOH/CoFe 2 O 4 adsorbent with porous CoFe 2 O 4 nanoparticles embedded on the AlOOH fibers using a simple hydrothermal technique and calcination process. The structural properties and surface characteristics of the AlOOH/CoFe 2 O 4 composites are detailedly analyzed by XRD, FTIR, XPS, TEM and SEM. Here, the high S BET and specific porous structure are beneficial to improve the adsorption performance of AlOOH/CoFe 2 O 4 adsorbents. Especially, when the molar ratio of AlOOH to CoFe 2 O 4 in the AlOOH/CoFe 2 O 4 fibers is 1:1, an optimal performance on adsorbing anionic Congo red (CR) and cationic methyl green (MG) dyes can be obtained at pH = 6.29, where the corresponding maximum adsorption capacities reach up to 565.0 and 423.7 mg g -1 , respectively. Factors leading to the change in the ability of adsorbing CR and MG dyes are systematically discussed, including contact time, temperature, initial concentrations, and pH values of the solutions. Meanwhile, the uptake of CR and MG dyes can best conform to Langmuir isotherm model and pseudo-second-order adsorption kinetics. The thermodynamic analysis verifies that the dye adsorption process is spontaneous and endothermic. Moreover, from the point view of practical application, the good reusability further makes the as-synthesized magnetic AlOOH/CoFe 2 O 4 composite be a perfect adsorbent with efficiently removing both anionic and cationic dyes from aqueous solutions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Determining the biomechanical properties of human tissues commonly involves the immersion or spraying of the tissues to maintain them in a hydrated state. However, the influence of the pH value of these solutions on the biomechanical properties of the tissues is not well understood. This study investigated the effects of the pH value on the biomechanical properties of the collagen-rich human iliotibial band (ITB). A total of 124 samples were allocated to polyethylene glycol (PEG) solutions of pH values between 3 and 13 for 24 h, which is a frequently used immersion time prior to biomechanical tests. After this, the samples were biomechanically tested in a uniaxial tensile testing setup using an established testing routine. Similarly, 69 samples were allocated to pH groups of 6, 7 and 8 and biomechanically tested after 1, 2 and 3 weeks. The cross-sectional area of all samples was determined after immersion into the PEG solutions for the specified time frames. In the 24-h experiment, the elastic modulus (pH 12: p ≤ 0.045; pH 13: p ≤ 0.020) and the ultimate tensile strength (pH 12: p ≤ 0.031; pH 13: p ≤ 0.026) of the pH groups 12 and 13 were significantly lower and their cross-sectional areas were higher (pH 12: p ≤ 0.005; pH 13: p ≤ 0.003) compared to several groups of acidic to alkaline pH values. There was no difference in the maximum forces between the different groups within a 24-h immersion time (p > 0.999). In the 3-week-test, a decrease of the ultimate tensile strength was noted between the 24-h and 3 week values for the pH groups 7 (p = 0.034) and 8 (p = 0.029). It is concluded that pH-dependent tissue swelling influences the cross-sectional area-dependent biomechanical properties of the human ITB. Therefore, the pH value of storage and hydration solutions for the preparation of biomechanical tests should be recorded. From a biomechanical perspective, the collagen stability of the human ITB is largely unaltered in PEG solutions with pH values between 3 and 13 over 24 h., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Atmospheric aerosol acidity impacts numerous physicochemical processes, but the determination of particle pH remains a significant challenge due to the nonconservative nature of the H + concentration ([H + ]). Traditional measurements have difficulty in describing the practical state of an aerosol because they comprise chemical components or hypotheses that change the nature of the particles. In this work, we present a direct pH measurement that uses water as a general probe to detect [H + ] in individual particles by micro-Raman spectroscopy. Containing the vibrational bands of ions and water influenced by ions, the spectra of hydrated ion were decomposed from the solution spectra as standard spectra by multivariate curve resolution analysis. Meanwhile, ratios of hydrated ions were calculated between the Raman spectra and standard spectra to evaluate concentration profiles of each ion. It demonstrated that good quantitative models between the ratio and concentration for all ions including H + can be built with correlation coefficients (R 2 ) higher than 0.95 for the solutions. The method was further applied to individual particle pH measurement. The pH value of sulfate aerosol particles was calculated, and the standard error was 0.09 using pH values calculated from the [HSO 4 - ] as a reference. Furthermore, the applicability of the method was proven by detecting the pH value of chloride particles. Therefore, utilizing water, the most common substance, as the spectroscopic probe to measure [H 4 ] without restriction of the ion system, this method has potential to measure the pH value of atmospheric particles with various compounds, although more work needs to be done to improve the sensitivity of the method.2- ] as a reference. Furthermore, the applicability of the method was proven by detecting the pH value of chloride particles. Therefore, utilizing water, the most common substance, as the spectroscopic probe to measure [H + ] without restriction of the ion system, this method has potential to measure the pH value of atmospheric particles with various compounds, although more work needs to be done to improve the sensitivity of the method., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Gallbladder cancer can be difficult to detect in its early stages and is prone to metastasize, causing bile duct obstruction, which is usually treated by stent implantation in clinic. However, the commonly used biliary stents are non-degradable, which not only prone to secondary blockage, but also need to be removed by secondary surgery. Biodegradable magnesium (Mg) is expected to one of the promising candidates for degradable biliary stents due to its excellent physicochemical property and biocompatibility. In this work, we studied the influence of high-purity Mg wires on gallbladder cancer through in vitro and in vivo experiments and revealed that the degradation products of Mg could significantly inhibit the growth of gallbladder cancer cells and promote their apoptosis. Our findings indicate that Mg biliary stent possesses the function of draining bile and treating gallbladder cancer, suggesting that Mg has good application prospects in biliary surgery. STATEMENT OF SIGNIFICANCE: Current research and development of biomedical magnesium are mainly concentrated in the cardiovascular and orthopedics field. Degradable magnesium bile duct stents have great application prospects in the treatment of bile duct blockage caused by bile duct-related cancers. At present, the effect of magnesium implants on gallbladder cancer is not clear. Our work verified the effectiveness of magnesium wire implants in inhibiting gallbladder cancer through in vivo and in vitro experiments, and studied the effect of magnesium degradation products on gallbladder cancer cells from the perspective of cell proliferation, apoptosis and cycle. This study provided new understanding for the application of magnesium in biliary surgery., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

The in vivo detection of small active molecules in plant tissues is essential for the development of precision agriculture. Tryptophan (Trp) is an important precursor material for auxin biosynthesis in plants, and the detection of Trp levels in plants is critical for regulating the plant growth process. In this study, an electrochemical plant sensor was fabricated by electrochemically depositing a polydopamine (PDA)/reduced graphene oxide (RGO)-MnO 2 nanocomposite onto a glassy carbon electrode (GCE). PDA/RGO-MnO 2 /GCE exhibited high electrocatalytic activity for the oxidation of Trp owing to the combined selectivity of PDA and catalytic activity of RGO-MnO 2 . To address the pH variability of plants, a reliable Trp detection program was proposed for selecting an appropriate quantitative detection model for the pH of the plant or plant tissue of interest. Therefore, a series of linear regression curves was constructed in the pH range of 4.0-7.0 using the PDA/RGO-MnO 2 /GCE-based sensor. In this pH range, the linear detection range of Trp was 1-300 μM, the sensitivity was 0.39-1.66 μA μM -1 , and the detection limit was 0.22-0.39 μM. Moreover, the practical applicability of the PDA/RGO-MnO 2 /GCE-based sensor was successfully demonstrated by determining Trp in tomato fruit and juice. This sensor stably and reliably detected Trp levels in tomatoes in vitro and in vivo, demonstrating the feasibility of this research strategy for the development of electrochemical sensors for measurements in various plant tissues., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Fluorescent pH probes have been served as powerful tools in biological and pathological studies in recent years due to the important roles of pH values in various physiological processes. Although plenty of pH probes have been delivered, development of two-photon ratiometric pH probes with large emission shift for detecting the variation of intracellular pH values is still a greatly challenging task. To address this concern, in this work, we have discovered a general strategy designing pH probes by means of a pH-dependent reversible intramolecular reaction of spiro-oxazolidine which can efficiently change their conjugation length and the electronic effect concurrently. To display the generality of the strategy, we have synthesized six pH probes, and all these probes exhibit short emission in basic conditions and dramatically red-shifted emission in acid environments. The emission shift of the six probes is more than 150 nm and even up to 210 nm, much larger than shift of all commercial and reported pH probes. The chemical sensing mechanism of intramolecular ring opening/closing reaction of spiro-oxazolidine has been confirmed with 1 H NMR spectra and density functional theory (DFT) calculations. Finally, we have used one of six with one- and two-photon properties to successfully image lysosomal pH changes under confocal and two-photon microscopes in a ratiometric manner. We believed that this spiro-oxazolidine strategy can serve as a general and powerful platform for the design of ideal pH probes., Competing Interests: Declaration of competing interest There are no conflicts of interest to this work. We declare that we do not have any commercial or associative interest that represents a conflict of interest in connection with the work submitted., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The influence of pH and dissolved oxygen (DO) on the degradation of ofloxacin (OFX) in water by UVA-LED/TiO 2 nanotube arrays photocatalytic fuel cell (UVA-LED/TNA PFC) was investigated. The degradation pathway depended on the location of OFX frontier orbital with different ionization states and the role of reactive oxidative species (ROSs) played with varied pH and DO values. In presence of DO, the quencher tests revealed that O 2 - played a key role at pH 3.0, 7.0 and 11.0, while OH made its greatest contribution at pH 3.0 and the effect of h + was largely inhibited at pH 11.0. Hydroxylation for cationic OFX was more significant, while demethylation and piperazinyl ring oxidation for anionic OFX occurred more quickly compared to other forms. Besides, zwitterionic OFX underwent decarboxylation and combination of demethylation & hydroxylation more easily. Much higher power generation was observed in presence of DO at pH 7.0, probably due to the enhanced adsorption of OFX on the TNA, and DO could amplify the electric potential between the two electrodes. The degradation efficiencies were almost the same in presence or absence of DO, but the pathways were different and e- aq may replace O 2 - as the leading ROSs in absence of DO., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objectives: Susceptibility testing is usually performed under standardized conditions for comparison of the activity of antimicrobial agents and the susceptibility of strains, but this does not reflect potential pathophysiological alterations at the infection site. While some impact factors have been studied already, there is a lack of knowledge about how different factors interact pharmacodynamically. We investigated the impact of albumin, pH and temperature in various combinations on the antimicrobial activity of glycopeptides., Methods: Determination of minimal inhibitory concentrations (MICs) and time-kill curves were performed for telavancin, vancomycin and teicoplanin using 20 clinical isolates of Staphylococcus aureus and ATCC29213. The impact of the addition of 12% albumin, pH reduction to pH6, and temperature ranging from 32°C to 42°C was studied and compared to the standard setting in the reference medium Mueller Hinton broth (MHB)., Results: At pH7 and 37°C the addition of albumin increased median MICs four-fold, eight-fold and two-fold for telavancin, teicoplanin and vancomycin, respectively. While changing temperature or pH alone had a moderate impact, the combination of albumin addition, pH decrease and temperature increase led to the maximum reduction of activity of 16-fold for teicoplanin compared to the standard setting. Temperature increase to 42°C increased the effect of albumin for teicoplanin and telavancin, resulting in ratios of 15.9 and 8. In contrast, reducing pH with concomitant albumin addition reduced the effect of albumin addition alone for telavancin, resulting in a ratio of 2 instead of 4., Conclusion: Combining different impact factors showed a highly heterogeneous impact on the activity of glycopeptides. It might be misleading to take only protein binding into consideration in pharmacokinetic/pharmacodynamic (PK/PD) models., (Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Aims: The impaired angiogenesis is the major cause of diabetic delayed wound healing. The molecular insight remains unknown. Previous study has shown that high glucose (HG) activates Na + /H + exchanger 1 (NHE1) and induces intracellular alkalinization, resulting in endothelial dysfunction. The aim of this study is to investigate whether activation of NHE1 in endothelial cells by HG damages the angiogenesis in vitro and in vivo., Methods and Results: We used western blot to detect the phosphorylations of both Akt and Girdin, and pH-sensitive BCECF fluorescence to assay NHE1 activity and pHi value, respectively. The angiogenesis was evaluated by measuring the number of tube formation in vitro, and blood perfusion by laser doppler and neovascularization by staining CD31 in vivo. Our results indicated that induction of intracellular acidosis (IA) increased p-Akt and p-Girdin in human umbilical vein endothelial cells (HUVEC). HG activated NHE1 and increased pHi value in a time-dependent manner, associated with the decreased phosphorylations of both Akt and Gridin, while inhibition of NHE1 by amiloride abolished the HG-induced reductions of p-Akt and p-Girdin. However, silence of Akt by siRNA transfection or pharmacological inhibitors (wortmannin and LY294002) bypassed IA-induced Girdin phosphorylation. Overexpression of constitutively active Akt abolished HG-reduced Girdin phosphorylation. In addition, upregulation of Akt or inhibition of NHE1 remarkably attenuated HG-impaired tube formation in HUVEC. In vivo study revealed that amiloride dramatically rescued hyperglycemia-delayed blood perfusion and neovascularization by augmenting ischemia-induced angiogenesis., Conclusion: IA promotes ischemia-induced angiogenesis via Akt-dependent Girdin phosphorylation in diabetic mice., (Copyright © 2018. Published by Elsevier B.V.)

Previously, we have studied protein adsorption behaviors on a series of poly(ethylenimine) (PEI)-grafted Sepharose FF, and a critical ionic capacity of PEI-grafted resins was observed, above which both protein adsorption capacity (q) and effective pore diffusivity (D e ) increased drastically. Moreover, reducing the charge density of the PEI-grafted resins from an ionic capacity of 740 mmol/L (FF-PEI-L740) to 440 mmol/L (FF-PEI-R440) by neutralization of the amino groups of PEI chains with sodium acetate brought out a three-fold increase of D e value at pH 8. In this work, FF-PEI-L740 and FF-PEI-R440 were selected to investigate the complicated effects of pH on protein adsorption behavior using bovine serum albumin (BSA) as the model protein. It was found that, for FF-PEI-L740, both the q and D e values decreased significantly when pH decreased from 9 to 5.5, and then increased dramatically at pH 5, and finally decreased remarkably at pH 4.5. The results were considered due to the following causes: The decrease of pH from 9 to 5.5 led to a greatly increased electrostatic repulsion between the PEI chains due to the increased dissociation degree of PEI, which caused the increase in steric hindrance effects and decrease in the bound protein transport by chain delivery. At pH 5, which was near the pI of BSA (∼4.9), the presence of few protein charges greatly decreased the electrostatic hindrance effect on protein transport and the high charge density of FF-PEI-L740 provided extensively accessible binding sites and facilitated the happening of chain delivery as well. At pH 4.5, the net charge of BSA shifted to positive, likely charged with PEI, so the overall electrostatic repulsion greatly hindered protein uptake. For FF-PEI-R440, whose charge density was much lower than FF-PEI-L740, its q and D e values even increased mildly when pH decreased from 8 to 5.5, because its slightly-increased charge density did not cause much increased electrostatic and steric hindrance effects but provided more binding sites for protein adsorption. At pH 5, the few charges of BSA and the low charge density of FF-PEI-R440 could not afford enough electrostatic interaction for protein binding, resulting in significantly decreased q and D e values. Besides, column breakthrough experiments revealed that FF-PEI-R440 kept high dynamic binding capacity (DBC) (>120 mg/mL) at pH 5.5-8, while FF-PEI-L740 offered high DBC (>80 mg/mL) at pH 5, 7 and 8 with a higher salt concentration (100 mmol/L NaCl). These findings demonstrated the excellence of FF-PEI-L740 and FF-PEI-R440 in different conditions, and would help in the design and selection of suitable resins for high-performance protein chromatography., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Introduction: The aim of this study was to compare the solubility and the change in pH of a tricalcium silicate-containing sealer (BioRoot RCS [BR]), a mineral trioxide aggregate-containing sealer (MTA Fillapex [MTA]), and an epoxy resin-based sealer (AH Plus [AH]) during a longer period of time., Methods: The solubility test was carried out in accordance with ISO6876:2012. Three hundred eighty sealer samples (n = 10 per group) were stored for 6 months in double distilled water (AD) or phosphate-buffered saline (PBS). The solubility was determined on the basis of the mass difference in percent. The pH measurement was carried out on the basis of the experimental setup of the solubility test with the aid of an electrode pH meter. The results were evaluated for significance by using analysis of variance, Student-Newman-Keuls, and t test (P < .05)., Results: The highest solubility was found for MTA in AD (4.65% ± 1.17%), followed by BR in AD (3.88% ± 0.42%) (P < .05). Also in PBS, MTA (3.24% ± 0.7%) showed a higher solubility than BR (1.78% ± 0.5%) (P < .05). AH was virtually insoluble during the entire period (0.5% ± 0.5%) (P < .05). The pH decreased continuously over time for all samples. After 6 months, BR showed the highest pH in AD (pH 10.3), followed by MTA in AD (pH 8.8), BR in PBS (pH 7.5), AH in PBS (pH 7.3), MTA in PBS (pH 7.2), and AH in AD (pH 6.3)., Conclusions: The solubility of MTA was significantly increased compared with BR and AH. Storage in PBS significantly reduced solubility of MTA and BR. BR showed a higher pH in both AD and PBS than MTA in AD and PBS. AH did not cause any significant pH change., (Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

In order to protect sperm chromosomes against degradation when they are being stored for relatively high temperatures, we investigated the optimal pH of the freeze-drying solution, EGTA/Tris-HCl buffered solution alkalinized by NaOH (Na-ETBS) or KOH (K-ETBS). Mouse spermatozoa suspended in Na-ETBS or K-ETBS were freeze-dried at pH 5.0-8.4 and stored at 4 °C or 50 °C for 3 days. Some freeze-dried samples were stored at 25 °C for 3 days or 1 month. After storage, samples injected into oocytes using intracytoplasmic sperm injection were assessed for chromosome damage in resulting zygotes. Irrespective of freeze-drying solutions and storage temperatures, almost all the zygotes (97-100%) produced using the spermatozoa freeze-dried at pH 5.0 had structural chromosome aberrations of sperm origin. When freeze-drying was conducted at pH 8.0-8.4 using Na-ETBS, the incidence of chromosome damage decreased to 14-17% in 4 °C storage and 24-26% in 50 °C storage. When freeze-dried in K-ETBS, the lowest level of chromosome damage occurred at pH levels of 7.7-8.4 at 4 °C storage (13-15%) and at pH 7.7-8.0 at 50 °C storage (16-23%). Spermatozoa freeze-dried in Na-ETBS at pH 8.2 and K-ETBS at pH 7.7 showed no significant increase in chromosome damage during 25 °C storage from 3 days to 1 month (11%-20% in Na-ETBS; 13%-18% in K-ETBS). Thus, use of the solutions optimized for short-term storage at high temperature (50 °C, 3 days) permits prolonged storage (1 month) of freeze-dried spermatozoa at room temperature., (Copyright © 2017 Elsevier Inc. All rights reserved.)

In order to clarify the influence of curing agents on the flavor of duck, the effect of pH on the surface hydrophobicity, secondary structures, and adsorption capacity of myofibrillar proteins to alcohols, aldehydes, ketones, and esters was assessed using Raman spectroscopy, gas chromatography-mass spectrometer, and other methodologies. The hydrophobicity decreased as pH increased from 5.0 to 8.0; β-turn turned into α-helix and random coil as pH increased from 5.0 to 7.0, while α-helix and random coil turned into β-sheet and β-turn as pH increased from 7.0 to 8.0. With the increase of pH, the decreased adsorbing of alcohols could depend on hydrogen bonds. As pH increased from 5.0 to 8.0, the increase of aldehydes and esters was attributed to the unfolding of myofibrillar proteins and decreased hydrophobicity. The decreased adsorbing of ketones was due to the decreased hydrophobicity as pH increased from 5.0 to 8.0. The present work provided information about the correlation between structure and adsorption capacity of myofibrillar proteins to flavor compounds., (© 2016 Poultry Science Association Inc.)

The aim of this study was to assess the feasibility of employing a novel but critical formulation pH (6.2) to encapsulate an anionic model drug (methotrexate, MTX) into chitosan(Cs)-tripolyphosphate nanoparticles(NPs). A response surface methodology using a three-level full factorial design was applied studying the effects of two independent variables namely; Cs concentration and MTX concentration. The responses investigated were the entrapment efficiency (EE%), mean hydrodynamic particle size (PS), polydispersity index (PDI) and zeta potential (ZP). In order to simultaneously optimize the series of models obtained, the desirability function approach was applied with a goal to produce high percent of MTX encapsulated into highly charged Cs-TPP NPs of homogenous optimum PS. MTX-loaded CsNPs were successfully prepared at the novel pH applied. The suggested significant models were found quadratic for EE, PS and ZP responses, while 2-factor interaction model for PDI. The optimization overlay graph showed that the maximum global desirability, D=0.856, was reached when the conditions were set at high Cs and MTX concentration. Thus, the use of such optimized conditions, at this novel pH, achieved a maximum drug EE% (73.38%) into NPs characterized by optimum PS (232.6nm), small PDI value (0.195) and highly surface charged (+18.4mV)., (Copyright © 2016 Elsevier B.V. All rights reserved.)

At a novel pH value of the polymeric solution (6.2), variable chitosan (Cs) and sodium tripolyphosphate (TPP) concentrations and mass ratios were optimized to improve the process yield without undesirable particle flocculation. Prepared formulations were characterized in terms of particle size (PS), zeta potential (ZP) and percentage yield (% yield). Artificial neural networks (ANN) were built up and used to identify the parameters that control nanoparticle (NP) size and yield, in addition to being tested for their ability to predict these two experimental outputs. Using these networks, it was found that TPP concentration has the greatest effect on PS and% yield. The most optimum formulation was characterized by a notable process yield reaching 91.5%, a mean hydrodynamic PS 227 nm, ZP+24.13 mv and spherical compact morphology. Successful Cs-TPP interaction in NP formation was confirmed by both Fourier transform-infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). This study demonstrated the ability of ANN to predict not only PS of the formed particles but also NP% yield. This may have a great impact on Cs-TPP NPs preparation and can be used to customize the required target formulations., (Copyright © 2016 Elsevier B.V. All rights reserved.)

The way the pH falls post-slaughter has an impact on meat quality. Pork longissimus muscles (n=48) were sorted in fast- (FG) (n=15) and normal glycolysing (NG) (n=33) muscles according to the post-slaughter pH 45 min values (FG<6.0; NG>6.0). FG muscles (5.84±0.04) compared with NG muscles (6.27±0.04) were accompanied with higher temperature, electrical conductivity, lightness and yellowness, and reduced grill loss and shear force values (P<0.05), but there were no pH-dependent changes of the drip loss and redness results. FG muscles had higher (P<0.05) percentages of fast-twitch glycolytic and lower proportions of fast-twitch oxidative and slow-twitch oxidative (P<0.05) muscle fibres. The study confirms the relationship of pH value to meat quality and muscle fibre characteristics also showing that pH values have no impact on intrinsic mitochondrial respiratory function.

To explore the controlled delivery of protein drugs in micro-environment established by osteoblasts or osteoclasts, the loading/release properties of bovine serum albumin (BSA) depending on pH environment were assessed. The adsorption amounts over mesoporous hydroxyapatite (MHA) or hydroxyapatite (HA) decreased as the pH increased, negatively correlating with zeta-potential values. The adsorption behavior over MHA fits well with the Freundlich and Langmuir models at different pHs. The results suggest that the adsorbed amount of protein on MHA or HA depended on the pH of protein solution. MHA adsorbed BSA at basic pH (MHApH 8.4) exhibited a different release kinetics compared with those in acid and neutral environments (MHApH 4.7 and MHApH 7.4), indicating that the release of protein could be regulated by environmental pH at which MHAs adsorb protein. MHApH 8.4 showed a sustained release for 6h before a gradual release when immersing in acidic environment, which is 2h longer than that in neutral environment. This suggests that MHApH 8.4 showed a more sustained release in acidic environment, which can be established by osteoclasts. The variation of adsorption strength between protein and MHA may be responsible for these behaviors. Our findings may be very useful for the development of MHA applications on both bone repair and protein delivery., (Copyright © 2014. Published by Elsevier B.V.)

Lairage time (short - 8min to 2.7h, n=28 vs. long - 14 to 21.5h, n=72) and pig handling (gentle - no use of stick or electric prod, pig not slipping, falling, nor emitting high-pitched vocalizations vs. rough - where any of these occurred) effects on pig stress and meat quality were measured. Blood lactate and cortisol, plus post-mortem pH (pH60min; pH24h), temperature (T60min), drip loss, sensory and instrumental color and meat quality for the longissimus dorsi, pars lumbalis derived meat were determined. Carcass rigor mortis and skin damages were measured. Lairage time significantly affected blood lactate, carcass rigor mortis, skin damages, drip loss, color and meat quality. Handling procedure influenced blood lactate, pH60min and T60min. Long lairage was more stressful, and was detrimental to carcass quality, but caused better meat quality compared to short lairage. Rough handling was related to higher lactate and lower meat quality., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

A new type of Eu(III) ofloxacin complex as the fluorescent pH indicator has been presented. Compared to pure ligand, the complex offers more distinguished color changes (green-red-blue) derived from both lanthanide line emissions and the secondary ionization steps of ofloxacin. During the concentration dependence experiments, the photoluminescence studies on the complex showed that the excitation of this pH probe can occur at a very long wavelength which extends to visible range (Ex=427 nm). Furthermore, the functional complex was successfully incorporated into soft networks and two novel luminescent hydrogels (rod and film) were fabricated. The soft materials also exhibited specific responses towards the pH variation. Finally, the onion cell-stain experiments were carried out to further confirm the validity of pH dependence and the results support the idea that the material will be suitable for monitoring biological samples in the future., (Copyright © 2014 Elsevier B.V. All rights reserved.)