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Aim: This study aimed to evaluate and compare fluoride ion release by Cention-N (self-cure and light-cure) and conventional glass-ionomer cement (GIC) at different pH levels and time intervals. Methodology: For fluoride release assessment, 240 samples (10 mm diameter, 2 mm height) of Cention-N and conventional glass-ionomer cement were created using rubber rings. Samples were stored in deionized water, and the cumulative fluoride ion release and change in pH were assessed using a spectrophotometer and pH meter, respectively, at the end of 7 days, 14 days, and 21 days. The obtained data were subjected to statistical analysis. Results: All three samples exhibited very high fluoride release in an acidic medium compared to the neutral medium. Although GIC demonstrated superior fluoride release, Cention-N displayed adequate fluoride release over a longer duration. Conclusions: Within the limitations of this study, it can be concluded that both Glass ionomer cement and Cention-N showed an initial fluoride burst.

Abstract Background The aim of this study was to evaluate the physicochemical properties of two newly introduced premixed calcium silicate-based root canal sealers (AH Plus Bioceramic Sealer and Bio-C Sealer) compared to a resin-based root canal sealer (ADseal root canal sealer). Methods Solubility, pH analysis, calcium ion release, and film thickness of each sealer were evaluated following ISO guidelines. The data were examined using the two-way ANOVA test. Furthermore, X-ray diffraction (XRD) examination was performed to investigate the crystalline phase of each type of sealer. X-ray fluorescence (XRF) analysis was done for the chemical elemental analysis of each sealer. Results The least film thickness, highest alkalinity, and highest calcium ion release were all displayed by AH Plus Bioceramic Sealer. High solubility, high alkalinity, intermediate calcium ion release, and intermediate film thickness were all displayed by Bio-C Sealer. While ADseal root canal sealer displayed the greatest film thickness, least solubility, alkalinity, and calcium ion release. Conclusions Both AH Plus Bioceramic Sealer and Bio-C Sealer represented adequate properties to be considered a good sealer that could be used as a potential alternative to resin-based root canal sealers.

Background: The aim of this study was to evaluate the physicochemical properties of two newly introduced premixed calcium silicate-based root canal sealers (AH Plus Bioceramic Sealer and Bio-C Sealer) compared to a resin-based root canal sealer (ADseal root canal sealer). Methods: Solubility, pH analysis, calcium ion release, and film thickness of each sealer were evaluated following ISO guidelines. The data were examined using the two-way ANOVA test. Furthermore, X-ray diffraction (XRD) examination was performed to investigate the crystalline phase of each type of sealer. X-ray fluorescence (XRF) analysis was done for the chemical elemental analysis of each sealer. Results: The least film thickness, highest alkalinity, and highest calcium ion release were all displayed by AH Plus Bioceramic Sealer. High solubility, high alkalinity, intermediate calcium ion release, and intermediate film thickness were all displayed by Bio-C Sealer. While ADseal root canal sealer displayed the greatest film thickness, least solubility, alkalinity, and calcium ion release. Conclusions: Both AH Plus Bioceramic Sealer and Bio-C Sealer represented adequate properties to be considered a good sealer that could be used as a potential alternative to resin-based root canal sealers. [ABSTRACT FROM AUTHOR]

Organic phosphates are an important component of soil phosphate reserves. We studied the sorption of three organic phosphates by goethite and by aluminium oxide and compared them with the sorption of inorganic phosphate (Pi). The organic phosphates were inositol hexa‐phosphate (IHP), glycerol phosphate (GlyP), and glucose‐6‐phosphate (G6P). We used five different initial pH values and 10 different initial concentrations. We measured both sorption and desorption. We used an equation which we call the Sibbesen‐Langmuir equation to successfully describe the observations over a 10,000 fold concentration range. Sorption increased the pH. The effects were largest at low pH and low initial concentration and were in the sequence Pi > IHP > G6P > GlyP. This sequence was a consequence of differences in ion size and mean charge. The different feedback effects of the different ions affected the shape of plots of sorption against concentration; similarity to the Langmuir shape was in the opposite sequence. Desorption curves always fell to the left of sorption curves; that is, there was always hysteresis. Part of this was an experimental artefact because desorption was measured at lower pH than sorption, but we provide evidence that this caused only part of the effect. The effects were greatest for Pi and least for IHP. We think that this hysteresis occurs because the adsorbed molecules diffuse into faults in the reacting medium. This would be more difficult for organic phosphate than for inorganic phosphate. Although hysteresis was smaller for organic phosphates, it was nevertheless substantial. We suggest that this is an important factor in their stability in soils. [ABSTRACT FROM AUTHOR]

Based on the response surface methodology, the pH change characteristics of coal-water slurry containing potassium permanganate (KMnO4) under the action of hydrogen sulfide (H2S) were studied, and the relationship between the factors of coal seam H2S content determination was explored. The effect coal rank, temperature and H2S inflow on the pH change of coal-water slurry was analysed. Through response surface methodology analysis, discovering H2S inflow had a significant effect on pH change of the solution, and the interaction between temperature and H2S inflow had a relatively significant effect on pH change of the solution. The optimal conditions were as follows: 36 mL H2S inflow, 36.5 °C temperature and medium rank coal. The conditions which had a significant effect on pH change of the solution, and compared with the experimental verification group, the error was small. Analyzing on influence factors of pH change of coal-water slurry, which provides a reference for the subsequent determination of H2S content. [ABSTRACT FROM AUTHOR]

Objectives: This paper reviews the chemical behaviour of glass polyalkenoate (glass-ionomer) dental cements, both conventional and resin-modified, in contact with natural tissues, with the aim of determining whether these materials can be considered to be bioactive. Data: Relevant papers describing the behaviour of bioactive glasses and ceramics, and glass-ionomer (glass polyalkenoate) cements have been identified using PubMed and Science Direct. This has allowed a comparison to be made between the behaviour of glass-ionomers and the speciality glasses and ceramics that are widely classified as bioactive, a designation considered valid for over fifty years. More recent papers concerning bioactive metals and polymers have also been studied and both in vitro and in vivo studies are included. Sources: Have included general papers on the chemistry and biological behaviour of bioactive glasses and ceramics, as well as papers on glass-ionomers dealing with (i) ion release, (ii) bonding to the surface of teeth, (iii) influence on surrounding pH and (iv) interaction with bone. Conclusion: The literature shows that glass-ionomers (glass polyalkenoates) have three types of behaviour that are similar to those of bioactive glasses as follows: Formation of direct bonds to living tissue (teeth and bones) without fibrous capsule; release of biologically beneficial ions; and change of the local pH. However, in in vitro tests, they do not cause calcium phosphate to precipitate from solutions of simulated body fluid, SBF. Despite this, studies show that, in patients, glass-ionomers interact chemically with hard tissues and this suggests that may indeed be considered bioactive.

Phosphorus (P) is an essential element needed by plants. The presence of phosphorus in the environment, especially soil in the form of bound phosphates. This condition can be affected by the acidity of the soil. Available phosphates can be released by phosphate solubilizing bacteria. EF.NAP 1 isolate is a phosphate-solubilizing bacteria that has been successfully isolated from acid soil in the area of the Institut Teknologi Sumatera (ITERA), Lampung, Indonesia, and potency as plant growth-promoting bacteria (PGPB). Based on the results of identification using the 16S rRNA gene, EF.NAP 1 isolates has similarities with Burkholderia territorii. These isolates were able to dissolve phosphate of 104.7 mg/L. P dissolution correlates with the growth phase of bacterial cells. During the phosphate dissolution process, the pH of the medium continues to increase, inversely proportional to the concept in general. The EF.NAP 1 isolate is able to produce six organic acids, i.e, acetic (339.14 mg/L), lactic (260.97 (mg/L), malic (133.24 mg/L), formic (31.52 mg/L), fumaric (19.31 mg/L) and tartaric acids (19.13 mg/L). B. territorii can produce IAA, nitrogenase, siderophore, HCN, chitinase, protease, and cellulose. The potency of B. territorii EF.NAP 1 as phosphate solubilizing bacteria and PGPB properties that have not been reported by others. [ABSTRACT FROM AUTHOR]

CO2 biomethanisation is a rapidly emerging technology which can contribute to reducing greenhouse gas emissions through the more sustainable use of organic feedstocks. The major technical limitation for in situ systems is that the reaction causes CO2 depletion which drives up pH, potentially leading to instability and even digestion failure. The study aimed to test fundamentally derived predictive equations as tools to manage H2 addition to anaerobic digesters. The methodology used data from the literature and from experimental digesters operated with excess H2 to a point of failure and subsequent recovery. Two equations were tested: the first relating pH to CO2 partial pressure (pCO2), and the second extending this to include the influence of volatile fatty acids and ammonia. The first equation gave good agreement for data from studies covering a wide range of operating conditions and digester types. Where agreement was not good, this could usually be explained, and in some cases improved, using the second equation, which also showed excellent predictive performance in the experimental study. The results validated the derived equations and identified typical coefficient values for some organic feedstocks. Both equations could provide a basis for process control of CO2 biomethanisation using routine monitoring of pH or pCO2 with additional analysis for volatile fatty acids and total ammonia nitrogen when required. [ABSTRACT FROM AUTHOR]

AIM: The aim of the present study was to examine the effect of alkasite material on the pH of the environment when used as a restorative material in different cavity preparations and prepared as a single block in standard sizes. METHODS: Alkalizing potential of the alkasite material was evaluated by restoring extracted teeth with three different restorative materials and preparing edentulous blocks. For this purpose, 30 extracted premolar teeth and silicone molds of standard size (2x2x4 mm) were used. One of the study groups consisted of edentulous alkasite blocks of standard size and the other three groups (O, OM, MOD) were alkasite restorations of cavities of different sizes. The teeth were divided into three groups according to the type of cavity preparation. Restoration of cavities and preparation of the blocks were performed according to Cention N (Ivoclar Vivadent) manufacturer’s instructions. All restorations and blocks were immersed individually in distilled water at pH 4. pH measurements were obtained using a pH meter (Sartorius, France) at 10-min, 20-min, 30-min and 60-min timepoints following immersion. Measurements were repeated for all four groups at the end of 24 hours, 48 hours and 7 days. RESULTS: Alkalizing effect was observed in all groups. pH changes after 24 hours, 48 hours and 7 days showed a significant difference among the groups at the measurement timepoints (p

Poly(NIPAM-co-AAC) (P(NI-AC)) was synthesized by changing the polymerization conditions using poly(N -isopropylacrylamide) (NIPAM) as temperature-responsive polymer and acrylic acid (AAC). Thermosensing color indicators, that changes color depending on the external temperature, were fabricated using P(NI-AC), a pH indicator, and agar. The pH of the P(NI-AC) aqueous solution increased above the lower critical solution temperature (LCST, 34°C), and a gradual pH rise and the shrinkage of aggregate diameter continued up to 70 °C under conditions with high AAC polymerization ratio. The LCST of P(NI-AC) aqueous solution with glucose decreased, and the discoloration temperature range of the thermosensing color indicator with glucose shifted to lower temperature side from 37 to 30°C. The LCST of polymer synthesized with NIPAM, AAC, and N , N -dimethylacrylamide (DMA) increased, and the discoloration temperature range of the thermosensing color indicator shifted to higher temperature side from 39 to 50°C. These results indicated that the discoloration temperature range was successfully adjusted by as much as 20 °C. [Display omitted] • Thermosensing color indicators were prepared using temperature-responsive polymer. • pH of temperature-responsive polymer solution changes with external temperature. • The desired discoloration temperature can be adjusted by changing the LCST. [ABSTRACT FROM AUTHOR]

Geological carbon sequestration in saline aquifers is one of the most promising strategies to help mitigate emissions of CO2 to the atmosphere. Significant challenges in ensuring the security of the sequestration process rest in the evolution and expansion of the CO2 plume in the subsurface. The ability to track the movement of the injected CO2 poses another challenge. Critical questions related to the integrity of the sequestration operations in saline aquifers relate to plume characteristics that can we monitor using well-based variables. We addressed this and related questions using an integrated modeling framework through a numerical investigation of carbon sequestration in saline aquifers during long-term and post-injection periods. This modeling paradigm incorporates the effect of structural, geological, and petrophysical characteristics. That way, we can account for critical physicochemical processes, rock-fluid interactions, and lithology dependencies. The well fluid variables investigated include fluid composition, pH, fluid density, and ion activity. We learned that fluid property analytics and diagnostics can be powerful tools to estimate the movement of CO2 and its storage in different trapping mechanisms. These analytics can help optimize operational aspects and simplify reservoir-scale models while still reflecting the complex nature of the CO2 interactions underground and offering insights into plume evolution.

INTRODUCTION: Fixed appliances have become an integral part of comprehensive orthodontic treatment as versatile tools that enable three-dimensional control of tooth movement. Fixed appliances are appliances that are attached to the teeth by cement or an adhesive material. Aligner is where an orthodontist or dentist, takes a mold of the patient's teeth and it is used to create a computerized tooth scan. The computerized model suggests stages between the current and desired teeth positions and aligners are created for each stage. The aim of the study is to estimate the pH and microbial change in conventional fixed appliances and aligners among patients undergoing orthodontic treatment in private dental colleges. MATERIALS AND METHODS: The subjects were asked to spit and the samples which were collected from each group using sterile containers and then for the microbial check it was streaked on different types of media such as Blood agar, Chocolate agar, MacConkey agar and Sabouraud media and it was then incubated aerobically for 24 hours at 37°C. The obtained saliva was put in 100ml of distilled water and litmus paper was dipped inside to observe the colour change for pH and the values were noted and analysed. RESULTS: The pH change was similar for both the groups, but the microbial change was comparatively less in case of aligners. CONCLUSION: The study had reported a low frequency of microbial change in aligners. This can be attributed to better hygiene practices and less plaque accumulation in aligners compared to the fixed appliances. [ABSTRACT FROM AUTHOR]

In the present investigation, induction furnace (IF) steel slag as coarse aggregate with 0%, 20% and 40% replaced concrete specimens of size 150 × 150 × 150 mm was prepared as an initiative to utilize iron-rich IF steel slag. The casted concrete specimens were cured for 28 days at room temperature (28 °C) in freshwater, and the obtained compressive strength is 22.5, 24.0 and 29.2 N/mm2, respectively. The blocks were then immersed in seawater under laboratory condition for 28 days, and variation in pH was monitored at regular intervals. The composition and mineralogical phases [quartz (SiO2), iscorite (Fe7SiO10), hematite (ε-Fe2O3) and almandine (Fe3Al2Si3O10)] present in IF steel slag were identified using XRF and XRD analysis, respectively. Surface morphology and elemental composition were studied using FESEM with EDAX analysis for before and after immersion of concrete blocks in seawater. Structural bonding of concrete blocks before and after immersion was studied using FTIR analysis. Compressive strength of concrete specimens after the immersion in seawater was evaluated and compared with before immersion in seawater. This initiative will be a major support for induction furnace steel industries via economic benefits. Utilization of iron-rich IF steel slag in marine concrete can be a vital candidate for the betterment of marine ecosystem via primary production of marine resources. [ABSTRACT FROM AUTHOR]

This study investigates the controlled release of α-chymotrypsin from an alginate hydrogel matrix. When protein molecules entrapped in the hydrogel matrix have a size smaller than the hydrogel pores, their hold/release from the polymer matrix are controlled by the electrostatic interaction between the guest molecules and host polymer. α-Chymotrypsin, as a model protein, was chemically modified with negatively charged species to change its pI and to convert its attractive interaction with a negatively charged alginate hydrogel matrix to a repulsion interaction allowing its release by pH-triggered signal. Then, bulk pH changes and electrochemically controlled local pH changes resulting from oxygen reduction were used for the controlled release of the enzyme from the alginate hydrogel. Three batches of modified α-chymotrypsin with different linker/enzyme ratios were synthesized, and their release profiles were investigated. The activity of both unmodified and modified α-chymotrypsin was evaluated using a UV–visible spectrophotometer following the standard procedure for the enzymatic assay of α-chymotrypsin (EC 3.4.21.1) and compared across all batches. Direct infusion electrospray ionization mass spectrometry (DI ESI-MS) was used to analyze the protein modifications and their impact on the isoelectric point values. [Display omitted] [ABSTRACT FROM AUTHOR]

Background Although airway hyperacidity may have a great effect in the pathogenesis of asthma, its evaluation may be difficult. This study was conducted at Mansoura University Hospitals aiming to evaluate the degree of asthma control by increasing pH in uncontrolled asthma cases by the use of inhaled NaHCO3 8.4% for 3 months. Patients and methods A total of 100 patients with asthma were included, and they were divided by simple randomization to 75 patients in study group and 25 controls. All participants were subjected to history taking, clinical examination, sputum cell count and pH assessment, PFT, high-resolution computed tomography, and sputum induction and NaHCO3 8.4% inhalation. Evaluation of asthma exacerbation 6 months before and after intervention was carried out. Results There was no significant difference between study and control groups regarding demographic data, all basic investigations, pulmonary function, or sputum total and differential cells. We found a significant increase of sputum pH after treatment in the study group. Furthermore, significant improvement of forced expiratory volume in 1 s, forced vital capacity, four parameters of control assessment, and exacerbation also was seen in the study group after treatment. There was a significant decrease of total cells and eosinophils in sputum in the study group. The linear regression model showed a significant negative correlation for all the studied factors except short-acting beta 2 (SABA) and day symptom improvement. Conclusion We conclude that the decrease of airway acidity by NaHCO3 8.4% leads to significant decrease in inflammatory cells and frequency of exacerbation and improves pulmonary function in poorly controlled bronchial asthma.

The droplet and creaming stability of food emulsions stabilized by mixed emulsifiers is a research hotspot in the field of emulsions. In this work, we mainly explore the effect of pH change on the droplet and creaming stability of fish oil-loaded emulsions synergetically (Span 80 and SL) or competitively (Tween 80 and SDS) stabilized by gelatin/surfactant. The results demonstrate that initial droplet stability and droplet storage stability, and creaming stability of the pH-adjusted emulsions are dependent on both the adsorption ways of emulsifiers and the adjusted pH: (1) Competitively stabilized emulsions have more stable droplets than synergetically stabilized emulsions; (2) SDS-dominant competitively stabilized emulsions have more stable droplets than gelatin-dominant emulsions; (3) Basic pH-adjusted emulsions have more stable droplets than acidic pH-adjusted emulsions; (4) The synergetically stabilized emulsions at acidic pH have significantly higher creaming indexes than that at basic pH; and (5) The competitively stabilized emulsions have high or similar creaming indexes to that at acidic pH. Further, the mechanisms are proposed according to Stokes’ Law. This work will provide useful information to understand the interfacial properties of mixed emulsifiers in the food emulsions and promising application perspective for the development of food beverages including acidic and alkali beverages.

Apoferritin is a complex protein potential for drug delivery application. The advantage of apoferritin lies in its core-shell structure, its nano size, and its pH-sensitivity. This study was aimed to characterize the structure of apoferritin due to the pH alteration effect in a solution using dynamic light scattering (DLS) and small-angle neutron scattering (SANS). Both DLS and SANS can observe protein size in solution near its physiological condition. The results show that apoferritin possesses a core-shell structure with a diameter of around 12–13 nm at pH 7. The dissociation of apoferritin occurs at pH 1.9. The SANS data shows the apoferritin at pH 1.9 was dissociated into the smaller oligomer. The structure of this smaller oligomer has a different configuration than the configuration of apoferritin subunits at pH 7. It can cause the failure of reassembly of apoferritin if the apoferritin is neutralized back to pH 7 after dissociation from pH 1.9.

Abstract Background Insolubility is the main requirement for ideal root end filling material to provide perfect sealing ability. Moreover, alkalinity and bioactivity provide great chance for tissues healing and remineralization. So, the aim of this work was to evaluate the chemical composition, solubility, pH change, and calcium ion release of recently introduced commercial mineral trioxide aggregate (MTA) endodontic repair cement (Harvard, Universal HandMix MTA) compared with ProRoot MTA repair material. Methods Solubility was evaluated after 7- and 14-day immersion time of specimens in phosphate buffer saline solution (PBS); the mean weight loss was evaluated and solubility was calculated as a percentage of the weight loss. For assessment of pH change and calcium ion release polyethylene tubes filled with the materials were soaked in distilled water for 7 and 14 days. Measurement of pH change was done by analytical pH meter. Concentrations of calcium ion release were measured using inductively coupled plasma optical emission spectroscopy. Data were statistically analyzed by independent sample t test and paired sample t test at 5% significance level. Results Harvard MTA endodontic cement showed significant lower solubility and higher pH values compared with that of ProRoot MTA. ProRoot MTA exhibited significant higher calcium ion release value after 14 days (P value ≤ 0.05). Conclusion Harvard, Universal HandMix MTA repair cement with its different chemical composition; exhibits a low solubility with enhanced alkaline pH value compared to ProRoot MTA repair material.

Aim: This study aimed to evaluate and compare fluoride ion release by Cention-N (self-cure and light-cure) and conventional glass-ionomer cement (GIC) at different pH levels and time intervals., Methodology: For fluoride release assessment, 240 samples (10 mm diameter, 2 mm height) of Cention-N and conventional glass-ionomer cement were created using rubber rings. Samples were stored in deionized water, and the cumulative fluoride ion release and change in pH were assessed using a spectrophotometer and pH meter, respectively, at the end of 7 days, 14 days, and 21 days. The obtained data were subjected to statistical analysis., Results: All three samples exhibited very high fluoride release in an acidic medium compared to the neutral medium. Although GIC demonstrated superior fluoride release, Cention-N displayed adequate fluoride release over a longer duration., Conclusions: Within the limitations of this study, it can be concluded that both Glass ionomer cement and Cention-N showed an initial fluoride burst., Competing Interests: There are no conflicts of interest., (Copyright: © 2024 Journal of Pharmacy and Bioallied Sciences.)

The present study purpose was to identify the flow characteristics of the drainage filter considering the characteristics of the landfill site, and to study the basic technology for efficient remediation of heavy metals. To this end, copper heavy metal was selected in consideration of landfill characteristics, and a study on flow characteristics was conducted using hydrophobic coated capillary tubes and microparticles. It was confirmed that the flow rate decreased as the pH increased at the hydrophobic surface, and pH 4, 6, and 8 flowed similarly in the center of the capillary tube, but decreased at pH 10. In the bottom part, it moved at the slowest speed of 1~4 μm/s and middle of center moved 17~25 μm/s. There was little change in flow in the CFD (Computational Fluid Dynamics) numerical analysis considering the surface contact angle, which is a hydrophobic characteristic, and the velocity coefficient was presented by regression analysis through the experimental results. In this way, the current study will be a basic examination of the selective remediation process of pH on hydrophobic coated surfaces. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study is to evaluate the effect of pH treatment on the formation of hydroxyapatite (HA) coating layer and the biodegradation rate of hydroxyapatite coated AZ31 alloy for applications in biodegradable implants. Methods: HA was grown on the surface of AZ31 substrate at three different pH solutions of 7.5, 9.0, and 10.5 respectively by chemical solution treatment method. The coated samples were evaluated their biodegradation behavior by immersion test in the simulated body fluid (SBF) for 14 days. The biodegradation rate of the samples during immersion test was observed by Mg2+ ion quantification method and measuring the increase of pH of the medium. Results: HA coatings were successfully grown on the AZ31 substrate at three different pH conditions. The sample coated at pH 7.5 showed its uniform and dense coating layer resulted in highest corrosion resistance. While the highest biodegradation rate was observed for the sample coated at pH 10.5 due to many micro-cracks formed in the HA layer. After 14 days of immersion, Mg(OH)2 and calcium phosphate were corrosion products on the surface of the specimens coated at pH 10.5 and pH 9.0 respectively. While HA almost remained on the surface of sample coated at pH 7.5. Conclusion: AZ31 alloy coated with HA at pH 7.5 has lowest biodegradation rate and become suitable for applications in biodegradable implants. [ABSTRACT FROM AUTHOR]

The aim of this study was to produce protein isolates from rainbow trout (Oncorhynchus mykiss) and to investigate its nutritional, structural, functional and sensory properties. Fish protein isolates were produced by pH change method using alkaline and acidic pHs (2.5, 3.5, 11 and 11.5). The extracted proteins were evaluated for nutritional value, and functional properties, sensory properties, color, and structural changes of proteins. The extracted proteins showed relatively high nutritional value in the amount of essential amino acids. The solubility, gelling and foaming capacity of the proteins depended significantly on its extraction pH. So that the percentage of solubility and foaming capacity of proteins extracted under alkaline conditions showed a higher rate than acidic conditions while the least gelation concentration was related to pH 11.5. Examination and comparison of color (L, a, b and whiteness) and sensory properties of isolated proteins showed that proteins at acidic pH had a brighter and whiter color and better sensory properties than those from alkaline pH. The change in pH caused extensive protein degradation as shown by FTIR and SEM. The above results showed that the protein isolated from rainbow trout waste has good functional and nutritional properties in alkaline conditions, while the sensory properties and color of acidic conditions showed better results. [ABSTRACT FROM AUTHOR]

Background: Insolubility is the main requirement for ideal root end filling material to provide perfect sealing ability. Moreover, alkalinity and bioactivity provide great chance for tissues healing and remineralization. So, the aim of this work was to evaluate the chemical composition, solubility, pH change, and calcium ion release of recently introduced commercial mineral trioxide aggregate (MTA) endodontic repair cement (Harvard, Universal HandMix MTA) compared with ProRoot MTA repair material. Methods: Solubility was evaluated after 7- and 14-day immersion time of specimens in phosphate buffer saline solution (PBS); the mean weight loss was evaluated and solubility was calculated as a percentage of the weight loss. For assessment of pH change and calcium ion release polyethylene tubes filled with the materials were soaked in distilled water for 7 and 14 days. Measurement of pH change was done by analytical pH meter. Concentrations of calcium ion release were measured using inductively coupled plasma optical emission spectroscopy. Data were statistically analyzed by independent sample t test and paired sample t test at 5% significance level. Results: Harvard MTA endodontic cement showed significant lower solubility and higher pH values compared with that of ProRoot MTA. ProRoot MTA exhibited significant higher calcium ion release value after 14 days (P value ≤ 0.05). Conclusion: Harvard, Universal HandMix MTA repair cement with its different chemical composition; exhibits a low solubility with enhanced alkaline pH value compared to ProRoot MTA repair material. [ABSTRACT FROM AUTHOR]

DNA release electrochemically stimulated by applying −10 mV on the modified electrode was studied. The release process was based on the local (interfacial) pH change produced upon H2O2 reduction electrocatalyzed by the immobilized microperoxidase‐11. SiO2 nanoparticles attached to the electrode surface and functionalized with trigonelline and boronic acid species changed their electrical charge from positive to negative upon the interfacial pH change, thus allowing electrostatic adsorption of negatively charged DNA on the positive interface and then its repulsion/release from the negative interface. The loaded/released DNA molecules were labeled with a fluorescent dye to allow easy detection of the released DNA molecules. The important feature of the developed system is the controlled DNA release upon applying very small electrical potential on the modified electrode. [ABSTRACT FROM AUTHOR]

In this study, the time-related pH changes that occur in cements having different structures were observed. Method and materials: Eight cements consisting of four permanent and four temporary cements were used. The materials were prepared according to manufacturers' instructions. The materials were used in 0.100 ± 0.02-g increments, with the purpose of standardizing the effect of massive differences. The 80 total specimens, including 10 from each cement type, were prepared, and the pH value of the distilled water was measured at 3, 10, 30, 60, and 120 minutes, and then again 24 hours later. Results: Analysis of variance showed the relation between the kind of cement and its pH change during the course of the study was statistically significant. Conclusion: Though temporary cements indicated neutral pH from the beginning of the study, the acidity of the other cements changed with time and took values approximate to neutral pH within 24 hours. (Quintessence Int 2004;35:753-757) [ABSTRACT FROM AUTHOR]

This works deals with analysis of properties of a carbon nanotube, the tips of which were functionalized by short cytosine-rich fragments of ssDNA. That object is aimed to work as a platform for storage and controlled release of doxorubicin in response to pH changes. We found that at neutral pH, doxorubicin molecules can be intercalated between the ssDNA fragments, and formation of such knots can effectively block other doxorubicin molecules, encapsulated in the nanotube interior, against release to the bulk. Because at the neutral pH, the ssDNA fragments are in form of random coils, the intercalation of doxorubicin is strong. At acidic pH, the ssDNA fragments undergo folding into i-motifs, and this leads to significant reduction of the interaction strength between doxorubicin and other components of the system. Thus, the drug molecules can be released to the bulk at acidic pH. The above conclusions concerning the storage/release mechanism of doxorubicin were drawn from the observation of molecular dynamics trajectories of the systems as well as from analysis of various components of pair interaction energies.

One of the main problems of waste stabilization ponds (WSP) is that they cannot remove nutrients when treating wastewater. Polishing ponds (PP) can efficiently remove nitrogen and phosphorus from effluents after efficient anaerobic pretreatment. It shown that the feasibility of nutrient removal is directly related to the pH that is established in the ponds. WSP normally operate at near neutral pH, but the biological processes that develop in PP tend to cause an elevation of pH and this, in turn, triggers the mechanisms of nutrient removal in ponds. In PP oxygen production by photosynthesis predominates over the oxidation of organic material. The net oxygen production has an equivalent CO2 consumption and this induces an increase in pH. The mechanism for nitrogen removal was identified as the desorption of ammonia from the liquid phase of the ponds. It was established that in ponds with a uniform concentration profile in the liquid phase the process developed in accordance with Fick’s law. The governing mechanism of phosphorus removal was precipitation with ions present in the wastewater, presumably calcium and magnesium. Polishing ponds can be operated with two different hydrodynamic regimes: flow-through (FTPP) and sequential batch (SBPP) ponds. The SBPP have the advantage that the pH elevation is more rapid, and that the final pH is higher.

The regeneration of soft tissues that connect, support or surround other tissues is of great interest. In this sense, hydrogels have great potential as scaffolds for their regeneration. Among the different raw materials, chitosan stands out for being highly biocompatible, which, together with its biodegradability and structure, makes it a great alternative for the manufacture of hydrogels. Therefore, the aim of this work was to develop and characterize chitosan hydrogels. To this end, the most important parameters of their processing, i.e., agitation time, pH, gelation temperature and concentration of the biopolymer used were rheologically evaluated. The results show that the agitation time does not have a significant influence on hydrogels, whereas a change in pH (from 3.2 to 7) is a key factor for their formation. Furthermore, a low gelation temperature (4 °C) favors the formation of the hydrogel, showing better mechanical properties. Finally, there is a percentage of biopolymer saturation, from which the properties of the hydrogels are not further improved (1.5 wt.%). This work addresses the development of hydrogels with high thermal resistance, which allows their use as scaffolds without damaging their mechanical properties.

Objectives: This paper reviews the chemical behaviour of glass polyalkenoate (glass-ionomer) dental cements, both conventional and resin-modified, in contact with natural tissues, with the aim of determining whether these materials can be considered to be bioactive., Data: Relevant papers describing the behaviour of bioactive glasses and ceramics, and glass-ionomer (glass polyalkenoate) cements have been identified using PubMed and Science Direct. This has allowed a comparison to be made between the behaviour of glass-ionomers and the speciality glasses and ceramics that are widely classified as bioactive, a designation considered valid for over fifty years. More recent papers concerning bioactive metals and polymers have also been studied and both in vitro and in vivo studies are included., Sources: Have included general papers on the chemistry and biological behaviour of bioactive glasses and ceramics, as well as papers on glass-ionomers dealing with (i) ion release, (ii) bonding to the surface of teeth, (iii) influence on surrounding pH and (iv) interaction with bone., Conclusion: The literature shows that glass-ionomers (glass polyalkenoates) have three types of behaviour that are similar to those of bioactive glasses as follows: Formation of direct bonds to living tissue (teeth and bones) without fibrous capsule; release of biologically beneficial ions; and change of the local pH. However, in in vitro tests, they do not cause calcium phosphate to precipitate from solutions of simulated body fluid, SBF. Despite this, studies show that, in patients, glass-ionomers interact chemically with hard tissues and this suggests that may indeed be considered bioactive., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:John Nicholson reports a relationship with GC Corp that includes: consulting or advisory. The other two 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., (© 2024 The Authors. Published by Elsevier Ltd.)

The present study purpose was to identify the flow characteristics of the drainage filter considering the characteristics of the landfill site, and to study the basic technology for efficient remediation of heavy metals. To this end, copper heavy metal was selected in consideration of landfill characteristics, and a study on flow characteristics was conducted using hydrophobic coated capillary tubes and microparticles. It was confirmed that the flow rate decreased as the pH increased at the hydrophobic surface, and pH 4, 6, and 8 flowed similarly in the center of the capillary tube, but decreased at pH 10. In the bottom part, it moved at the slowest speed of 1~4 μm/s and middle of center moved 17~25 μm/s. There was little change in flow in the CFD (Computational Fluid Dynamics) numerical analysis considering the surface contact angle, which is a hydrophobic characteristic, and the velocity coefficient was presented by regression analysis through the experimental results. In this way, the current study will be a basic examination of the selective remediation process of pH on hydrophobic coated surfaces.

Physical hydrogels are supramolecular materials obtained by self-assembly of small molecules called gelators. Aromatic amino acids and small peptides containing aromatic rings are good candidates as gelators due to their ability to form weak bonds as π-π interactions and hydrogen bonds between NH and CO of the peptide chain. In this paper we show our results in the preparation of a transparent hydrogel that was obtained by self-assembly of a fluorine-containing dipeptide that relies on the additional formation of halogen bonds due to the fluorine atoms contained in the dipeptide. We used Boc-D-F2Phe-L-Oxd-OH (F2Phe = 3,4-difluorophenylalainine; Oxd = 4-methyl-5-carboxy-oxazolidin-2-one) that formed a strong and transparent hydrogel in 0.5% w/w concentration at pH = 4.2. The formation of a hydrogel made of unnatural fluorinated amino acids may be of great interest in the evaluation of patients with parkinsonian syndromes and may be used for controlled release.

Highlights • A method via flushing followed by calcination in humid N 2 was used to modify ACF. • Effects of modification parameters on pH change of sanitary soak were investigated. • Possible mechanism of reducing pH change of soaking solution was clarified. • Modified ACFs under optimized conditions meet sanitary standards for drinking water. • This method can efficiently reduce soaking pH change and improve COD removal. Abstract The safety of drinking water plays a vital role in human health. Activated carbon fibers (ACF) have been widely used in the field of water purification. However, current filter elements of water purifier made by ACF have an unqualified pH change which fails to meet sanitary soak standard and low COD removal rate. Considering the perspective of converting surface functional groups and adjusting composition of ACF, a facile method via flushing followed by calcination in humid nitrogen atmosphere was used to modify ACF. The effects of some parameters including washing method, type of flushing water, flushing time, water content of calcined sample, calcination temperature and time were investigated, and possible mechanism of reducing pH change of soaking solution was clarified by characterizing the ACF samples before and after flushing and calcinations using Boehm titration, XPS, TG/DTA-MS, BET, FTIR and IC analysis. The results show that some ions and fire retardants in ACF were effectively removed and surface functional groups were converted from acidic to basic ones by this method. Water in ACF was found to play an important role in promoting the release of gases and facilitating the conversion of functional groups in the calcination process. The pH changes of all the modified ACF (M-ACF) and filter elements of water purifier made by the M-ACF under optimized modification conditions met sanitary soak standard and COD removal rate obviously increased. This economical and practical modification method for solving unqualified soaking pH change and low COD removal problems of ACF filter elements of water purifier has great significance in the field of drinking water purification. [ABSTRACT FROM AUTHOR]

Serratia marcescens forms different colony patterns under distinct conditions. One of them is the concentric fountain-shaped pattern with pigmented center followed by unpigmented ring and pigmented rim. In this work, we study this pattern formation by construction of the mathematical model able to display this pattern based on putative metabolical traits, supported by series of experiments and by references. A pattern formation of such colony type depends on the disposition of glucose and amino acids, and is accompanied by a pH change in the agar medium. In this paper, we confirm that a metabolic activity of growing colony alters its environment which subsequently changes the colony formation. Presented model corresponds well with the real colony behaviour. [ABSTRACT FROM AUTHOR]

The anthropogenic release of atmospheric CO 2 affects soil nutrient cycling through varied biogeochemical processes. Cation depletion from exchange sites, carbonate mineral dissolution, and subsequent changes in organic and inorganic carbon flux are growing concerns for soil health and sustainability. Particularly, the effects of acid deposition on soil pH and soil health under changing global carbon flux is poorly understood. To estimate the magnitude and effects of pH change across different soil profiles, the depth-wise response of soil cations, pH, and soil inorganic carbon (SIC) to varying CO 2 levels was investigated using column-leachate experiments. Six soils, representing acidic, neutral, and alkaline pH, were exposed to different CO 2 enrichments (100%, 10%, 1%, and Control) of water percolate for 30 days. Analysis of the column leachates revealed that the base cations (Ca, Mg, Na) were higher initially than on day 30, while Si leaching increased with time. The pH in leachates tended to attain an equilibrium state with time under CO 2 saturation, indicating the buffering capacity of alkaline and neutral soils. Evaluation of the soil before and after the experiments showed that the solid SIC, such as carbonate minerals and any dissolved SIC components (e.g., carbonate, bicarbonate ions) entrained in the pore space increased, whereas the potential cation exchange capacity (PCEC) decreased in all soils. This trend was especially prominent for alkaline soils at 100% CO 2 enrichment. Over the short-term study, the SIC showed minimal response to varying CO 2 enrichment conditions in neutral and acidic soils. The altered cation concentrations in the leachates suggest that under long-term exposure to elevated CO 2 , a deficiency of cationic essential plant nutrients such as Ca2+, Mg2+, and K+ is likely, especially with low buffering capacity and primary mineral content. In contrast, an increase in nutrient solubility and elemental toxicity (e.g., Al3+ Mn) can be observed in the short term. The initial soils with greater ECEC experienced an increased SIC leaching in the shorter term and suggested potential deposition in deeper layers. The resultant SIC loss might be amplified in arid to semi-arid soils with low SIC and affect soil health. [Display omitted] • A significant amount of cations was released from soils saturated with CO 2. • The soil cation exchange capacity (CEC) decreased with time under CO 2 enrichment. • Alkaline soil pH slightly tends to the equilibrium state (neutral) at CO 2 enrichment. • Inorganic carbon increased mostly at 100% CO 2 enrichment in alkaline soils. • CO 2 -induced acidity influences soil weathering potential and subsequent precipitation. [ABSTRACT FROM AUTHOR]

Local pH is stated to acidify after bone fracture. However, the time course and degree of acidification remain unknown. Whether the acidification pattern within a fracture hematoma is applicable to adjacent muscle hematoma or is exclusive to this regenerative tissue has not been studied to date. Thus, in this study, we aimed to unravel the extent and pattern of acidification in vivo during the early phase post musculoskeletal injury. Local pH changes after fracture and muscle trauma were measured simultaneously in two pre-clinical animal models (sheep/rats) immediately after and up to 48 h post injury. The rat fracture hematoma was further analyzed histologically and metabolomically. In vivo pH measurements in bone and muscle hematoma revealed a local acidification in both animal models, yielding mean pH values in rats of 6.69 and 6.89, with pronounced intra- and inter-individual differences. The metabolomic analysis of the hematomas indicated a link between reduction in tricarboxylic acid cycle activity and pH, thus, metabolic activity within the injured tissues could be causative for the different pH values. The significant acidification within the early musculoskeletal hematoma could enable the employment of the pH for novel, sought-after treatments that allow for spatially and temporally controlled drug release.

Aim of the Study: Metabolic acidosis is associated with increased mortality in critically ill patients. We hypothesized that early correction of acidosis of presumed metabolic origin results in improved outcomes. Patients and Methods: We conducted a prospective, observational study from February 2015 to June 2016 in a 12 bed mixed intensive care unit (ICU) of a 1000 bed tertiary care hospital in the north of India. ICU patients aged above 18 years with an admission pH ≥7.0 to <7.35 of presumed metabolic origin were included. Arterial blood gas parameters including pH, PaO2, PaCO2, HCO3−, Na+, K+, Cl−, anion gap (AG), base excess, and lactate at 0, 6, and 24 h along with other standard laboratory investigations were recorded. The primary outcome was to assess the impact of early pH changes on mortality at day 28 of ICU. Results: A total of 104 patients with 60.6% males and 91.3% medical patients were included in the study. Sepsis of lung origin (60.6%) was the predominant etiology. By day 28, 68 (65.4%) patients had died. Median age was 49.5 years, weight 61.7 kg, Sequential Organ Failure Assessment, and Acute Physiologic and Chronic Health Evaluation II scores were 16 and 12, respectively. Nonsurvivors had a higher vasopressor index (P < 0.01), lactate and central venous oxygen saturation (P < 0.05), and lower pH (P < 0.05). A pH correction/change of ≥1.16% during the first 24 h had the best receiver operating characteristic for predicting survival at day 28, with area under the curve (95% confidence interval, 0.72 [0.62–0.82], P < 0.05) compared to HCO3-, BE, lactate, and AG. Conclusions: Metabolic acidosis is associated with higher mortality in ICU. The rate of change in pH may better predict ICU mortality than other metabolic indices. [ABSTRACT FROM AUTHOR]

A series of poly( N,N -dimethyl acrylamide- co -methacryloyl sulfadimethoxine) (poly(DMA- co -SDM)) hydrogels with different ratios of N,N -dimethylacrylamide (DMA) and methacryloyl sulfadimethoxine monomer (SDM) were synthesized by free radical polymerization. The pK a values of the monomer and hydrogels were measured to investigate the extent to which their pH-responsive properties were affected by the ionizable sulfonamide groups. Further, buffer solutions of pH 2.0–10.0, considered as the spoilage metabolites, were used to confirm the change in the pH-responsive properties. The composition ratios of DMA and SDM strongly affected the pK a values of the hydrogels, contributing to differences in the ionization around their pK a values. As a result, all the hydrogels showed different changes in their appearance, from opaque to transparent or vice versa at certain pH values. The change in the transparency of the as-prepared hydrogels is strongly dependent on both the change in the pH and the amount of buffer solution, which mainly occurs owing to the change in the quality of a product with time. Therefore, the synthesized pH-responsive poly(DMA- co -SDM) hydrogels can be potentially applied as transparency changing indicators in response to metabolites released owing to the change in the quality of the food products. [ABSTRACT FROM AUTHOR]

The Meliponini honey is one type of stingless bee honey. Although honey has been widely used as a natural remedy, understanding on how storage affect the microbiological quality and pH in stingless honey is still scarce. This study was carried out to determine the microbial quality of honey produced by stingless bees, Heterotrigona itama and Geniotrigona thoracica during ambient storage for 6 weeks. The changes in microbiological analysis was determined for Aerobic Plate Count (APC), yeast count and Bacillus count. Lactic acid bacteria (LAB) were isolated using three types of media, namely, MRS agar, MRS agar with 0.8% CaCO3 and MRS agar with 1% glucose. Detection of Clostridium was done using anaerobic egg-yolk agar and cook meat medium. Results showed that Aerobic Plate Count ranged between 10² to 105 CFU/g for both samples. However, yeast count showed the range between 10² to 106 CFU/g, which higher than APC. Both honey samples showed low in Bacillus count. The LAB counts on three media were significantly higher for the first month of storage, then decreased gradually after fifth week. Storage of honey had reduced the pH in both honey samples to pH 2. Clostridium was not detected in all samples. [ABSTRACT FROM AUTHOR]

Glyphosate has significant adverse effects on creature and ecological balance. Therefore, the efficient treatment of glyphosate wastewater is of great significance. In this study, nano calcium peroxide (n-CaO 2) was loaded onto activated sludge biochar (SBC), and then Fe(II) was added to construct a Fenton-like system (n-CaO 2 /SBC/Fe(II)). SBC played the role of both a dispersant and catalyst, which greatly improved the removal capability of glyphosate. The removal efficiency of glyphosate in the n-CaO 2 /SBC/Fe(II) system was as high as 99.6%. The persistent free radicals (PFRs) on SBC can promote the conversion of Fe(III) to Fe(II) in the reaction system, and Fe(II) can be maintained at about 15 mg L−1 until the reaction reached equilibrium. Due to the synergistic effect of Fe(II) hydrolysis and SBC catalysis, n-CaO 2 /SBC/Fe(II) system can effectively remove glyphosate in a wide initial pH range (4.0–10.0), and the pH of the reaction system can be remained in a suitable environment (4.0–6.0) for Fenton-like reaction. Advanced oxidation and chemical precipitation were the main mechanisms for the removal of glyphosate. Most of glyphosate could be oxidized into H 2 PO- 4 anions by breaking the bonds of C–P and C–N, and the H 2 PO- 4 can be further adsorbed and bounded on the surface of the composites. This system overcomes the shortcomings of pH rising and Fe(III) precipitation in the CaO 2 -based oxidation systems, and realizes the efficient and complete degradation for glyphosate. [Display omitted] • n-CaO 2 /SBC/Fe(II) system can efficiently and completely degrade glyphosate. • PFRs on SBC can promote the conversion of Fe(III) to Fe(II) in the reaction system. • The pH of the solution can be well maintained in an environment (4.0–6.0) suitable for a Fenton-like reaction. • Glyphosate degradation is a synergistic process of advanced oxidation and chemical precipitation. [ABSTRACT FROM AUTHOR]