Desired pH Research Articles

Influence of buffer on colloidal stability, microstructure, and rheology of cellulose nanocrystals in hyaluronic acid suspensions

Hyaluronic acid (HA) is a natural biopolymer found in various human tissues, while cellulose nanocrystals (CNCs) extracted from pulp fibers have unique rheological properties and biocompatibility. Due to the superior biomechanical properties of CNC and HA, a CNC-based HA suspension may be useful in biomedical applications. While buffers are an essential constituent of any suspension used for biomedical applications to maintain the desired pH level, they can significantly affect the properties of the suspension, including colloidal stability, microstructure, and rheological characteristics.To our knowledge, this is the first study analyzing the influence of buffer solutions on the suspension characteristics of HA/CNC systems, integrating both theoretical and experimental approaches. The results revealed an alignment between predictions of the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory and results from experiments characterizing a buffer-specific trend in colloidal stability. Suspensions with a higher energy barrier showed higher colloidal stability, with a lower tendency for phase separation and agglomerate formations. The microstructural analysis of CNC tactoids in the suspension revealed the existence of the hedgehog defect when dispersed in different buffer solutions. The defect is predicted to be caused by the pH-dependent protonation and deprotonation of HA. Furthermore, steady shear viscometry showed a microstructural-dependent shear viscosity trend, which, in turn, depends on the buffer solution.The study provides novel insights into the microstructural and bulk properties of HA and CNC suspensions in various buffer solutions. The results highlight the importance of solvent choice in tailoring the properties of the suspension for specific biomedical applications. These findings may be helpful in formulating HA and CNC suspensions for different biomedical applications, including drug delivery systems and viscosupplement injections.

PH-Sensitive Fluorescent Probe in Nanogel Particles as Theragnostic Agent for Imaging and Elimination of Latent Bacterial Cells Residing Inside Macrophages.

Rhodamine 6G (R6G) and 4-nitro-2,1,3-benzoxadiazole (NBD) linked through a spacer molecule spermidine (spd), R6G-spd-NBD, produces a fluorescent probe with pH-sensitive FRET (Förster (fluorescence) resonance energy transfer) effect that can be useful in a variety of diagnostic applications. Specifically, cancer cells can be spotted due to a local decrease in pH (Warburg effect). In this research, we applied this approach to intracellular infectious diseases-namely, leishmaniasis, brucellosis, and tuberculosis, difficult to treat because of their localization inside macrophages. R6G-spd-NBD offers an opportunity to detect such bacteria and potentially deliver therapeutic targets to treat them. The nanogel formulation of the R6G-spd-NBD probe (nanoparticles based on chitosan or heparin grafted with lipoic acid residues, Chit-LA and Hep-LA) was obtained to improve the pH sensitivity in the desired pH range (5.5-7.5), providing selective visualization and targeting of bacterial cells, thereby enhancing the capabilities of CLSM (confocal laser scanning microscopy) imaging. According to AFM (atomic force microscopy) data, nanogel particles containing R6G-spd-NBD of compact structure and spherical shape are formed, with a diameter of 70-100 nm. The nanogel formulation of the R6G-spd-NBD further improves absorption and penetration into bacteria, including those located inside macrophages. Due to the negative charge of the bacteria surface, the absorption of positively charged R6G-spd-NBD, and even more so in the chitosan derivatives' nanogel particles, is pronounced. Additionally, with a pH-sensitive R6G-spd-NBD fluorescent probe, the macrophages' lysosomes can be easily distinguished due to their acidic pH environment. CLSM was used to visualize samples of macrophage cells containing absorbed bacteria. The created nanoparticles showed a significant selectivity to model E. coli vs. Lactobacillus bacterial cells, and the R6G-spd-NBD agent, being a mild bactericide, cleared over 50% E.coli in conditions where Lactobacillus remained almost unaffected. Taken together, our data indicate that R6G-spd-NBD, as well as similar compounds, can have value not only for diagnostic, but also for theranostic applications.

Modulation of Electron Push-Pull by Redox Non-Innocent Additives for Long Cycle Life Zinc Anode.

Application of an aqueous Zn-ion battery is plagued by a water-induced hydrogen evolution reaction (HER), resulting in local pH variations and an unstable electrode-electrolyte interface (EEI) with uncontrolled Zn plating and side reactions. Here, 4-methyl pyridine N-oxide (PNO) is introduced as a redox non-innocent additive that comprises a hydrophilic bipolar N+-O- ion pair as a coordinating ligand for Zn and a hydrophobic ─CH3 group at the para position of the pyridine ring that reduces water activity at the EEI, thereby enhancing stability. The N+-O- moiety of PNO possesses the unique functionality of an efficient push electron donor and pull electron acceptor, thus maintaining the desired pH during charging/discharging. Intriguingly, replacing ─CH3 (electron pushing +I effect) by ─CF3 group (electron pulling ─I effect), however, does not improve the reversibility; instead, it degrades the cell performance. The electrolyte with 2m ZnSO4 + 15mm PNO enables symmetric cell Zn plating/stripping for a remarkable > 10 000h at 0.5mA cm-2 and exhibits coulombic efficiency (CE) ≈99.61% at 0.8mA cm-2 in Zn/Cu asymmetric cell. This work showcases the immense interplay of the electron push-pull of the additives on the cycling.

Voriconazole and Beauvercin Loaded Niosomal Mucoadhesive Nanogel as an effective Treatment for the Management of Oral Candidiasis

Oral candidiasis is a fungal infection, which affects the oral mucosa. The main causative agent of this is Candida albicans and as the literature indicates highest prevalence of Candida bloodstream infections in India. Most commonly azole derivatives such as miconazole, fluconazole, itraconazol etc. are used to manage the infection. However, their efficacy is compromised due to multidrug resistance. A new azole derivative voriconzole could be effective but its poor water solubility and bioavailability are seen as significant limitations. Its efficacy can be enhanced by combining it with beauvericin, a cyclic hexadepsipeptide with remarkable antifungal activity against candida. One study reported that combining of beauvericin with voriconzole reduce the MIC of voriconazole by 128th times. Furthermore the solubility and bioavailability were enhanced by loading both the drugs in niosomes. The niosomes were imcorporated into a polymeric mucoadhesive gel post statistically optimization by the Box-Behnken experimental design. The niosomes were subjected to evaluation for vesicular size, surface morphology, entrapment efficiency, drug release and zeta potential High entrapment efficiency was observed in the optimized noisome formulation F3 (89.89±0.64 % for voriconazole and 92.98±0.35 % for beauvericin) exhibiting cumulative drug release of 79.98±1.87 % for voriconazole and 69.17±1.98 % for beauvericin. The mucoadhesive gel was smooth, homogenious with desired pH and mucodhesion. The stability studies indicated that all the formulations are stable as evidence by no significant change in drug content over the time. These findings suggest that a niosmal mucoadhesive gel loaded with voriconazole and beauvericin is a good therapeutic delivery system for the effective treatment of oral candidiasis.

Machine-Learning-Assisted Rational Design of Si─Rhodamine as Cathepsin-pH-Activated Probe for Accurate Fluorescence Navigation.

High-performance fluorescent probes stand as indispensable tools in fluorescence-guided imaging, and are crucial for precise delineation of focal tissue while minimizing unnecessary removal of healthy tissue. Herein, machine-learning-assisted strategy to investigate the current available xanthene dyes is first proposed, and a quantitative prediction model to guide the rational synthesis of novel fluorescent molecules with the desired pH responsivity is constructed. Two novel Si─rhodamine derivatives are successfully achieved and the cathepsin/pH sequentially activated probe Si─rhodamine─cathepsin-pH (SiR─CTS-pH) is constructed. The results reveal that SiR─CTS-pH exhibits higher signal-to-noise ratio of fluorescence imaging, compared to single pH or cathepsin-activated probe. Moreover, SiR─CTS-pH shows strong differentiation abilities for tumor cells and tissues and accurately discriminates the complex hepatocellular carcinoma tissues from normal ones, indicating its significant application potential in clinical practice. Therefore, the continuous development of xanthene dyes and the rational design of superior fluorescent molecules through machine-learning-assisted model broaden the path and provide more advanced methods to researchers.

Multifunctional Adjuvants Affect Sulfonylureas with Synthetic Auxin Mixture in Weed and Maize Grain Yield.

A field study in the years 2017-2019 was carried out to evaluate the impact of novel adjuvant formulations on the efficacy of sulfonylurea and synthetic auxin herbicides. Treatments included nicosulfuron + rimsulfuron + dicamba (N+R+D) at full and reduced rates with three multicomponent (TEST-1, TEST-2, TEST-3) as well as standard (MSO, S) adjuvants. In this greenhouse study, Echinochloa crus-galli seeds were planted and treated with N+R+D at 2-3 leaf stages. The water with the desired pH (4, 7, and 9) for the preparation of the spray liquid was prepared by incorporating citric acid or K3PO4 to either lower or raise the pH of the water. Adjuvant TEST-1 added to the spray liquid at pH 4 increased the effectiveness to 68%, TEST-2 to 81%, and TEST-3 to 80%, compared to 73% and 66% with the MSO and S. The efficacy of N+R+D at pH 7 with TEST-1 increased to 83%, TEST-2 to 82%, and TEST-3 to 77%, but with MSO, it increased to 81%, and 71% with S. Adjuvants TEST-1, TEST-2, and TEST-3 in the liquid at pH 9 increased efficacy to 76 and 80%, compared to 79 and 63% with MSO or S adjuvants. N+R+D applied with TEST-1, TEST-2, and TEST-3 provided greater weed control than herbicides with surfactant (S) and similar or even better than with standard methylated seed oil (MSO) adjuvants. Maize grain yield after herbicide-with-tested-adjuvant application was higher than from an untreated check, and comparable to yield from herbicide-with-MSO treatment, but higher than from S treatment.

Design and Implementation of Large-Scale Hard Rock AMD Dewatering and REE Production

To develop a domestic Rare Earth Elements (REE) supply chain the Hydraulic Preconcentrate (HPC) produced at the Horseshoe bend treatment plant (HSB) was evaluated as a potential source for feedstock. After the clarifiers were flipped to the desired pH set points, a total of 24 Geobags were repeatedly filled and allowed to passively dewater. The Geobags evaluated were comprised of a mix of Woven, Non-woven, and Capillary Channel Fiber (CCF). The bags were constructed with either a composite of woven and nonwoven or only woven geotextile. Half of the bags of both types also included “fins” made of CCF to evaluate their impact on dewatering. Column Filtration Tests (CFTs) were performed onsite to provide laboratory value for hydraulic conductivity. Throughout their dewatering, the geobags were sampled to determine their rate of dewatering. Influent samples from HSB were also tested to produce a Specific Gravity (Gs), via pycnometer testing and Grain Size Distribution (GSD), via sieve and hydrometer analysis. The dewatering ability of the geobags was high regardless of bag material with a mean total solids percentage of approximately 40% across all samples after only one month of dewatering. The GSD performed on the HPC is gap graded with most particles having a diameter of approximately 0.5-0.05mm. Hydraulic conductivity values for the filter cakes during Column Filtration Testing ranged from 0.5 to 2.5 meters/day. This data will help to guide development of future large-scale HPC dewatering and the parametric design of an REE oxide production plant at the HSB site.

Dry fermented vegetable products of long-term storage and their integration into the diet of astronauts

Relevance. Fermentation makes it possible to improve the properties of the final product, increase its nutritional value and organoleptic characteristics. It has been scientifically proven that the use of fermented foods (with high nutritional and biological value) on a regular basis has a positive effect on human health, increases immunity, improves the functioning of the gastrointestinal tract. Dry fermented products with a long shelf life can be recommended as part of the diet in space. The aim is to creation of a dry base for fermented long-term storage beverages based on cabbage and table carrots, applicable in the diet of space nutrition. Objects and methods of research. The objects of the study were the domestic hybrid of white cabbage F1 Severyanka and the domestic variety of carrot table Margosha, and the dry fermented products obtained from them. Results. It was found that, according to biochemical and organoleptic quality indicators, the domestic hybrid of white cabbage F1 Severyanka and the domestic carrot variety Margosha are suitable for various types of processing, including fermentation and manufacture of dried fermented products. The comparison of the number of microorganisms in fermented cabbage and cabbage dehydrated by LTVD (low temperature vacuum drying) and VFD (vacuum freeze drying methods was carried out. The survival rate of microorganisms was 1.62 times higher in LTVD. The ways of accelerating the fermentation process of table carrots are considered. The expediency of using starter cultures obtained on the basis of the fermented product has been confirmed. It has been found that using starter cultures in the form of a fermented product dried by the LTVD method accelerates fermentation and allows you to reach the desired pH level 1.33 times faster than the base one and does not affect the final organoleptic characteristics.

Unravelling pH/pKa influence on pH-responsive drug carriers: Insights from ibuprofen-silica interactions and comparative analysis with carbon nanotubes, sulfasalazine, and alendronate

This study employs density functional theory to explore the interaction between ibuprofen (IBU) and silica, emphasizing the influence of the trimethylsilyl (TMS) functional group for designing pH-responsive drug carriers. The surface (S) and drug (D) molecules' neutral (0) or deprotonated (−1) states were taken into consideration during the investigation. The likelihood of these states was determined based on the pKa values and the desired pH conditions. To calculate the pH-dependent interaction energy (EintpH), four different situations have been identified: S0D0, S0D−1, S−1D0, and S−1D−1.The electrostatic component of interaction energy aligns favorably with its theoretical value in both the Debye-Hückel and Grahame models. The investigation has gathered first-hand experimental data on the drug loading and release of pH-responsive mesoporous silica nanoparticles. Effective drug loading was observed in the acidic environment of the stomach (pH 2–5), followed by a release in the slightly basic to neutral pH of the small intestine (pH 7.4), These findings align with existing literature. The results revealed horizontal drug adherence on silica surfaces, improving binding capabilities. Comparisons were made with combinations involving carboxylated carbon nanotubes and ibuprofen, silica, and sulfasalazine, and silica and alendronate, exploring drug loading/release dynamics associated with positive/negative interaction energies. The investigation, supported by experimental data, contributes valuable insights into pH-responsive mesoporous silica nanoparticles, offering new design possibilities for drug carriers.

Measuring local pH at interfaces from molecular tumbling: A concept for designing EPR-active pH-sensitive labels and probes.

Molecular probes and indicators are broadly employed for pH measurements in bulk media and at interfaces. The underlying physical principle of pH measurements of most of these probes is based on a change in the electronic structure that, for example, results in a shift of the emission peak of the fluorescence probes, changes in NMR chemical shifts due to the affected electronic shielding, or magnetic parameters of pH-sensitive nitroxides as measured by EPR. Here we explore another concept for measuring local protonation state of molecular tags based on changes in rotational dynamics of electron spin-bearing moieties that are readily detected by conventional continuous wave X-band EPR. Such changes are especially pronounced at biological interfaces, such as lipid bilayer membranes, due to the probe interactions with adjacent charges and polarizable dipoles. The concept was demonstrated by synthesizing a series of pH-sensitive nitroxides and spin-labelled phospholipids. EPR spectra of these newly synthesized nitroxides exhibit relatively small - about 0.5 G - changes in isotropic nitrogen hyperfine coupling constant upon reversible protonation. However, spin-labelled phospholipids incorporated into lipid bilayers demonstrated almost 6-fold change in rotational correlation time upon protonation, readily allowing for pKa determination from large changes in EPR spectra. The demonstrated concept of EPR-based pH measurements leads to a broader range of potential nitroxide structures that can serve as molecular pH sensors at the desired pH range and, thus, facilitates further development of spin-labelling EPR methods to study electrostatic phenomena at chemical and biological interfaces.

Local electrochemical sample acidification for the detection of Pb2+ traces.

Electrochemical detection of pollutants (e.g. heavy metals) in real samples often requires the adjustment of pH to allow optimal sensitivity. Such sample pretreatment can be challenging for on-site applications as it implies the use of valves, pumps and storage of base or acid solutions. We report here the use of an electrochemical approach for the control of water sample pH. It offers the possibility for local pH adjustment while simultaneously detecting Pb2+, whose detection sensitivity is pH dependent. An effective electrochemical method through local electrochemical acidification is performed to detect Pb2+ within a desired pH range without the need to add chemical reagents. Local acidification is based on water electrolysis. An anodic potential is applied to an acidifier to rapidly electrogenerate protons. This allows the sample pH to be tailored to the optimal detection condition. Reduction of the Pt oxide layer formed on the acidifier is key to obtain repeatable results in Pb2+ detection. On-site sample acidification is combined with anodic stripping voltammetry to reach a detection limit of 6 ppb (30 nM), which is lower than the World Health Organization guideline value for Pb2+ level in drinking water.

Quality by Design Assisted Development of Luliconazole Transethosomes in Gel for the Management of Candida albicans Infection.

The objective of this study was to develop and evaluate a novel vesicular formulation of luliconazole (LUL) for the management of Candida albicans infection through a topical route. LUL-loaded transethosomes (LUL-TE) were prepared by the film hydration method and various independent and dependent variables were optimized using the Box-Behnken design. Selected critical material attributes were the content of phospholipids (X1), concentration of ethanol (X2), and amount of sodium cholate (X3). Formulated LUL-TE were characterized for percent entrapment efficiency, percent drug loading, vesicle size, and polydispersity index (PDI) and were incorporated into the carbomer gel base and further evaluated for gel characterizations. The prepared transethosomal gel (LUL-TE-CHG) was evaluated for pH, spreadability, viscosity, antifungal activity, and in vitro study. From the observed results, it was evident that the prepared LUL-TE-CHG was in the desired pH (6.2 ± 0.45), spreadability [8.3 ± 0.42 g/(cm·s)], viscosity (236.1-19.2.26 mPa·s), nanovesicle size (252 ± 9.82), entrapment efficiency (85% ± 5.24%), zeta potential (-34.05 ± 3.52 mV), and PDI (0.233 ± 0.002). The zone of inhibition results suggested that the LUL-TE-CHG formulation has the highest antifungal activity, that is, 5.83 ± 0.15 mm3. The in vitro results showed that drug release within 2 h was 18.1% ± 2.0% and after that sustained release action, 83.2% ± 1.7% within 8 h. Finally, to confirm the therapeutic efficacy of the developed formulation, fungal infection was induced by using C. albicans in Wistar rats. In vivo, skin irritation study and histopathology studies were performed in the disease-induced model. Animal experiments revealed that LUL-TE-CHG has significantly improved the diseased condition in Wistar rats. The results observed from the skin permeation and skin deposition profile ensure that the prepared novel LUL-loaded TE system had a higher permeation rate and increased retention time compared with LUL-CHG. The hydrogel incorporated with LUL could be a novel approach with safe and effective fungal treatment.

Dual Microfluidic Sensor System for Enriched Electrochemical Profiling and Identification of Illicit Drugs On-Site.

Electrochemical sensors have emerged as a new analytical tool for illicit drug detection to facilitate ultrafast and accurate identification of suspicious compounds on-site. Drugs of abuse can be identified using their unique voltammetric fingerprint at a given pH. Today, the right buffer solution is manually selected based on drug appearance, and in some cases, a consecutive analysis in two different pH solutions is required. In this work, we present a disposable microfluidic multichannel sensor system that automatically records fingerprints in two pH solutions (e.g., pH 5 and pH 12). This system has two advantages. It will overcome the manual selection of a buffer solution at the right pH, decrease analysis time, and minimize the risk of human errors. Second, the combination of two fingerprints, the superfingerprint, contains more detailed information about the samples, which enhances the selectivity of the analytical technique. First, real-time pH measurements proved that the sample can be brought to the desired pH within a minute. Subsequently, an electrochemical study on the microfluidic platform with 1 mM illicit drug standards of MDMA, cocaine, heroin, and methamphetamine showed that the characteristic voltammetric fingerprints and peak potentials are reproducible, also in the presence of common cutting agents. Finally, the microfluidic concept was validated with real confiscated samples, showing promising results for the user-friendly identification of drugs of abuse. In short, this paper presents a successful proof-of-concept study of a multichannel microfluidic sensor system to enrich the fingerprints of illicit drugs at pH 5 and pH 12, thus providing a low-cost, portable, and rapid identification system of illicit drugs with minimal user intervention.

Predicting the Base Neutralization Capacity of Soils Based on Texture, Organic Carbon and Initial pH: An Opportunity to Adjust Common Liming Recommendation Approaches to Specific Management and Climate Conditions

Liming is an effective measure to increase the soil pH and to counterbalance soil acidification. Therefore, the liming recommendations (LRs) for agricultural practice consider two aspects: changing the initial pH to the desired pH and compensating for all pH decreases taking place within the liming interval. The separation of these aspects is essential to optimize LRs and to minimize lime losses to the environment. Therefore, we developed a pedotransfer function (PTF) to calculate the lime demand to change the initial pH to the desired pH and compared the results with the LRs for agricultural practice. Applying this PTF to a set of 126 soil samples that were analyzed for base neutralization capacity could explain approximately 78% of the variability in the pH changes after the addition of different amounts of Ca(OH)2. Consequently, the lime demand to change the initial pH to the desired pH increased by approximately one-sixth compared to the lime demand proposed by the liming recommendation scheme, which is commonly used in Germany. From the numerical difference between the lime demand according to the LRs and the PTF, we calculated the annual acidification rates based on the soil texture, organic matter content and initial pH. Decoupling the abovementioned two aspects of LRs might be helpful to optimize the LRs by adapting to different regions, diverse management strategies and a changing climate.

Enhancing the functionality of plant-based Yogurt: Integration of lycopene through dual-stage fermentation of soymilk

Well-defined compositional assemblies of plant-based yogurt are of fast-growing awareness for world population concerning environmental sustainability, economic burdens and health risks. Soybean is an attractive candidate for plant yogurt, suffering from poor flavor, limited nutrition, and undesired allergens to offer healthy-functional segments. Herein, we deciphered a novel lycopene-soy yogurt by efficient two-stage fermentation of engineered B. subtilis and LAB. The fortified sogurt was ensured with redundant lycopene of 22.67 ± 2.95 mg/g DCW by engineered B. subtilis and enriched soy isoflavone from synergistic effects of engineered B. subtilis and LAB, possessing strong antioxidant capacity for upgrading functionality. Moreover, the desired pH, accelerated protein hydrolysis, enhanced amino acid availability, and expected sensory attributes cooperatively conferred lycopene-soy yogurt as healthy functional food. High potential is firstly ascribed to sequential dual culture of engineered B. subtilis and LAB in lycopene-soy yogurt, in which flavorful, hypoallergenic and antioxidative ingredients enabled functionalities for plant-based yogurt.

Exploring the Possibility of Enriching Fermented Milks with Young Barley Leaves Powder Preparation

Barley (Hordeum vulgare L.) is one of the first cereals that humans began to cultivate. This study aimed to investigate the possibility of enriching fermented dairy products, using fermented milk as an example, with young barley leaves powder (YBLP) preparation including different starter cultures of lactic acid bacteria (LAB). The addition of YBLP did not affect the maximum rate of acidification and the time at which the maximum acidification rate was achieved. However, it did impact the time required to reach the desired pH level (4.6) for specific starter cultures. Over a 28-day storage period, gradual acidification of the fermented milk was observed. The addition of YBLP has a limited effect on the pH of the fermented milk, with the pH value primarily dependent on the type of starter culture and storage time. The addition of YBLP may have a positive effect on the survival of bacterial cells during the storage of the fermented milk; however, a gradual decrease in the number of LAB cells was observed during refrigerated storage. Furthermore, the addition of YBLP had a significant effect on the hardness, adhesion, and water-holding capacity of some fermented milk immediately after fermentation, depending on the specific starter culture used.

Improving physical stability of pea protein-based emulsions near the isoelectric point via polysaccharide complexation

Development of plant protein-based mildly acidic beverages remains challenging as the pH range falls near the protein isoelectric point, destabilizing emulsions. To overcome this problem, it was hypothesized that complexation between plant proteins and polysaccharides could provide emulsion stability in this critical pH range. Four different polysaccharides (sugar beet pectin, gum Arabic (GA), guar gum, gellan gum) were mixed separately with pea protein isolate (PPI) in 1:1 ratio, and the critical pH values for the formation of soluble complexes were determined. Heating the mixture widened the optimal pH range for soluble complexation for pectin-PPI and GA-PPI below the isoelectric point, which was then used to prepare 5 wt% O/W emulsions with an aqueous phase containing 0.5 wt% biopolymers at pH 8.0 and pH 4.5. Emulsion stability was characterized using droplet size, charge, visual observation, microstructure, and accelerated gravitational separation. PPI-only emulsions were stable at pH 8.0 but extensively destabilized at pH 4.5. The GA-PPI emulsions showed high stability at pH 8.0; however, at pH 4.5, the soluble complexes failed to provide a stable emulsion due to extensive droplet aggregation and phase separation. The emulsion prepared with a co-soluble pectin-PPI mixture at pH 8.0 also showed droplet aggregation and phase separation. The most improved emulsion stability (smallest droplet size, no aggregation) was observed for the pectin-PPI soluble complex at pH 4.5. Findings from this study showed that soluble complexes could be obtained at the desired pH range depending on the polysaccharide sources, which can stabilize O/W emulsions even near the protein's isoelectric point.

P-271 How much should you tolerate? The tolerance level of gas mixtures percentage in premixed gases

Abstract Study question Does the percentage of tolerance level of gas mixtures for premixed gas affect blastocyst formation rate? Summary answer A lower percentage of gas tolerance level can improve the blastocyst formation rate by providing a more optimal pH in the culture microenviroment. What is known already Benchtop incubators that use premixed gases are regarded as one of the most common incubators used in many IVF setups. The level of CO2 in the mixture has a direct impact on the media’s pH whereby an increase in the CO2 level will result in a lower pH and vice versa. Most media companies require a percentage of 6.0-6.5% to achieve an acceptable pH range of 7.2-7.4 for optimal culture microenvironment. However, it is often taken for granted that the CO2 and pH of the medium is within the acceptable range due to the “certificate” provided by these gas companies. Study design, size, duration This is a retrospective study looking at the average blastocyst formation rate from January 2018-December 2022 on 1665 cycles. Participants/materials, setting, methods The total MII collected and inseminated was 21,631. The mean women’s age was 37 ± 4.2 years old. All the embryos were cultured in the same laboratory conditions using BT 37 Planer (Origio) and K-Minc (Cook) incubators. From January 2018 to July 2020, all the patient’s embryos were cultured with premixed gas of 5% tolerance level (n = 940) and from Aug 2020-December 2022, all of the embryos were cultured with premixed gas of 2% tolerance level (n = 725). Main results and the role of chance It was found that the average blastocyst rate was significantly increased when the gas tolerance level was 2% (57.09%) when compared to when the gas tolerance level was 5% (52.11%) (p < 0.05). Limitations, reasons for caution Different gas companies may use different methods of measuring the gas percentage levels. Therefore, it is advisable to be cautious and impose internal QC on the gas mixture percentage on individual cylinders. Wider implications of the findings A lower gas tolerance level may provide a more optimal accuracy of gas percentage to achieve the desired pH for embryo culture and to improve IVF outcomes. Trial registration number not applicable

Ammonia recovery from source-separated hydrolyzed urine via a dual-membrane distillation in-series process

This study presents a dual membrane distillation (MD) in-series process to recover ammonia from source-separated hydrolyzed urine. The first MD stage separates and recovers ammonia from the hydrolyzed urine using an acid solution, while the second MD stage helps dewater the acid solution with captured ammonia and maintain its solution pH. The feed temperature and pH were optimized for operational conditions. The specific ammonia transfer (SAT) value was evaluated to obtain comparative results. While the water fluxes of both the single and dual-MD in-series set up systems were similar, the dual-MD in-series module showed higher SAT values and ammonia fluxes. At pH = 6, the ammonia flux values were minimal, but at pH = 13.2, they significantly increased to over 180 g/m2 h for the dual-MD in-series setup, which was approximately twice as much as the single MD setup (about 100 g/m2 h). In addition, the ammonium concentration in dual-MD in-series setup rose to over 200 mg/L at pH around 9, which is twice higher than that of a single MD setup. The results demonstrated that during the experiment, the dual-MD in-series configuration could help maintain the acid collector pH around 3 while for a single setup it continuously increased and reached to over 8 after 4 h. This innovative design not only preserves the desired pH range but also minimizes the amount of acid consumed, making it a promising approach in advancing nutrient recovery from human urine.

Enhanced photocatalytic efficiencies in a bifunctional ZnO/PVA nanocomposites derived from Capparis zeylanica L.

The modern food sector demands versatile nanocomposites of polymers for food to wrappers to inactivate germs linked to foods in order to ensure quality throughout the packaging process. Recently, it has become quite appealing to use zinc oxide nanocomposite with polyvinyl alcohol (PVA) assistance for food storage containers. Variable combinations of zinc acetate and Capparis zeylanica leaf extract (3:1, 1:7, 1:3, and 1:1) were used to create nanostructured ZnO at the desired pH (10.5). ZnO/PVA nanocomposites films were created with different weight % of (16, 13, 9 and 5%) ZnO nanoparticles by using solution casting method. The generated ZnO and ZnO/PVA nanocomposites (NCs) were characterized using analytical techniques like X-ray diffraction spectroscopy (XRD), ultraviolet spectroscopic analysis (UV–Vis), Fourier-transform infrared analysis (FT-IR), and field emission scanning electron microscopic study (FE-SEM). The generated ZnO and ZnO/PVA NCs were tested for their efficacy as antibacterial agents against Gram + ve (Streptococcus pyogenes, Staphylococcus aureus) and Gram -ve (Pseudomonas aeruginosa, and E. coli) bacteria. Under UV–visible irradiation, the methylene blue (MB) breakdown caused by the fabricated undoped ZnO and ZnO/PVA nanomixture was investigated. The FE-SEM investigation for synthesized ZnO from a 1:1 ratio exhibited spherical shaped appearance. However, the nanocomposite made with 5% ZnO showed equally scattered nanoflake particles in the matrix of PVA film as well as on the surface. The XRD results showed that ZnO synthesized with a higher proportion of plant extract produced smaller crystallites, whereas ZnO synthesized with a lower percentage of plant extract produced bigger crystallite sizes. The optimum concentration for the breakdown of methylene blue (MB) among the various concentrations examined was 5% ZnO/PVA. Furthermore, a study of the biomedical efficiency of undoped ZnO and ZnO/PVA revealed that 5% ZnO/PVA had the potential antibacterial efficacies.