pH Correction Research Articles

A Fully-Printed Wearable Bandage-Based Electrochemical Sensor with pH Correction for Wound Infection Monitoring

HighlightsThe first example of a flexible array capable of detecting pyocyanin, a bacterial virulence factor, while correcting dynamic pH fluctuations.Developed a screen-printable conductive nanocomposite ink for fabricating the pyocyanin sensor and utilized a polyaniline/carbon nanocomposite as a pH-sensitive film for the pH sensor.Customized inks are advantageous in terms of flexible printed sensing array integrated onto a bandage surface, capable of monitoring both pyocyanin and pH levels in wound exudate.

LDHzyme-assisted high-performance on-site tracking of levodopa pharmacokinetics for Parkinson's disease management

Parkinson's disease (PD) is a progressive neurodegenerative disorder marked by the loss of dopaminergic neurons and the consequent decline in motor and cognitive functions. The primary therapeutic agent levodopa necessitates precise dosing due to its narrow therapeutic window and complex pharmacokinetics. This study presents the development of a novel CuCoFe-LDHzyme-based sweat sensor for real-time monitoring of levodopa concentration in PD patients. Employing differential pulse voltammetry (DPV) technique, the sensor demonstrates high sensitivity and selectivity, achieving a detection limit of 28.1 nM. The sensor's design allows for non-invasive, continuous monitoring, significantly enhancing patient convenience compared to traditional blood sampling methods. Through pH correction, precise quantification of levodopa in sweat is accomplished, and a strong correlation (Pearson coefficient = 0.833) with blood levodopa levels is established. The pharmacokinetic profile of levodopa is reconstructed in real-time, offering a promising tool for optimizing PD treatment regimens. This study highlights the potential of CuCoFe-LDHzyme sensors to advance personalized treatment strategies, aiming to improve the quality of life for PD patients by providing clinicians with real-time data for medication adjustments.

Determination of multiple analytes in urine using label-free SERS coupled with simple sample pretreatments

BackgroundA key restriction of label-free surface-enhanced Raman spectroscopy (SERS) in analysis of objects with complex composition (including with several target analytes) is the competition of mixture components for interaction with SERS-active surface. This leads to poor selectivity of the analysis of such mixtures (e.g., body fluids) and the need to use advanced sample pretreatment procedures such as HPLC or TLC. Therefore, this work aims to develop a set of simple and fast pretreatment steps (dilution, pH correction, etc.) to increase the sorption of the target analyte, reduce the sorption of admixtures, and prevent suppression of the target analyte SERS signal. ResultsWe have developed label-free SERS assay suitable for the determination of three analytes (methotrexate, cephalosporin antibiotic, and creatinine) in one real urine sample as a model matrix with complex and deviating composition. The choice of drugs is justified by the need to monitor their concentration in urine during joint drug treatment of cancer patients with concomitant bacterial infection, while monitoring creatinine concentration helps to evaluate kidney function of the patients. Additionally, three cephalosporin representatives were used in the study to maximize versatility of the assay. As a results, the optimized pretreatment steps enable to eliminate the negative influence of excess of interferences (including other analytes) and achieve precise (≤12 % RSD) and accurate (88–111 % recovery) determination of several analytes in the therapeutically relevant ranges: 300–3000 μg mL−1 for creatinine, 20–200 μg mL−1 for methotrexate and cephalosporins. SignificanceTherefore, in addition to reporting a new SERS assay for the analysis of body fluids, this study clearly demonstrates the importance of taking into account competitive adsorption processes on the SERS substrate surface. We suggest making this practice mandatory when developing any label-free SERS assay because it enables to maximize the selectivity and accuracy of the analysis as well as to simplify the analysis procedure.

Mitochondrial oxidative phosphorylation capacity in skeletal muscle measured by ultrafast Z-spectroscopy (UFZ) MRI at 3T.

To investigate the feasibility of rapid CEST MRI acquisition for evaluating oxidative phosphorylation (OXPHOS) in human skeletal muscle at 3T, utilizing ultrafast Z-spectroscopy (UFZ) combined with MRI and the Polynomial and Lorentzian line-shape Fitting (PLOF) technique. UFZ MRI on muscle was evaluated with turbo spin echo (TSE) and 3D EPI readouts. Five healthy subjects performed in-magnet plantar flexion exercise (PFE) and subsequent changes of amide, PCr, and partial PCr mixed Cr (Cr+) CEST dynamic signals post-exercise were enabled by PLOF fitting. PCr/Cr CEST signal was further refined through pH correction by using the ratios between PCr/Cr and amide signals, named PCAR/CAR, respectively. UFZ MRI with TSE readout significantly reduces acquisition time, achieving a temporal resolution of <50 s for collecting high-resolution Z-spectra. Following PFE, the recovery/decay times (τ) for both PCr and Cr in the gastrocnemius muscle of the calf were notably longer when determined using PCr/Cr CEST compared to those after pH correction with amideCEST, namely = 87.1 ± 15.8 s and = 98.1 ± 20.4 s versus = 32.9 ± 19.7 s and = 43.0 ± 13.0 s, respectively. obtained via 31P MRS ( = 50.3 ± 6.2 s) closely resemble those obtained from pH-corrected PCr/Cr CEST signals. The outcomes suggest potential of UFZ MRI as a robust tool for non-invasive assessment of mitochondrial function in skeletal muscles. pH correction is critical for the reliable OXPHOS measurement by CEST.

A novel integrated material flow cost accounting (MFCA)- IoT-lean management system approach to improving water use efficiency and reducing costs in the beverage industry

The purpose of this study is to present a novel approach of integrating Material Flow Cost Accounting (MFCA), Internet of Things (IoT) and lean management systems to improve water use efficiency and reduce costs in the beverage industry. The positive and negative product costs of water purification, syrup manufacture, concentrate mixing, and packing were analyzed. The MFCA analysis showed 78.5% positive and 21.5% negative product costs. The use of the Power BI application to display real-time positive and negative costs in each process, scenario modeling and simulation was able to promote water savings and cost reductions, as well as supporting factory team ideation for choosing one of three improvement plans: 1) RO flushing water recovery in water purification; 2) water conservation with automated pH correction at packaging warmer; or 3) wastewater treatment and reuse of the rejected RO brine. According to our two-scenario water conservation testing, an automation process could improve pH adjustment in the packaging process, while MFCA, IoT, and lean management systems could be applied to improve industrial water use efficiency, demonstrating the potential for sustainable water use. The beverage-industry case in the present study validated this approach, resulting in a 24.1% production rate increase and a 4.5% cost reduction of 71,010 THB savings per year.

The Use of Beech Bark (Latin: Fagus sylvatica) and Birch Bark (Latin: Betula pendula Roth) for the Removal of Cationic Dyes from Aqueous Solutions

The aim of this work was to determine the sorption capacity of the cationic dyes Basic Red 46 (BR46) and Basic Violet 10 (BV10) on the prepared sorbents: beech bark (BBe) and birch bark (BBi). Two fractions of bark were used in the research: fine (2–3 mm) and coarse (4–5 mm). The carried out tests made it possible to determine the influence of the pH value on the sorption efficiency, the sorption equilibrium time and the maximum sorption capacity of the two tested sorbents. The Langmuir model and the Freundlich model were used to describe the obtained experimental data. Beech and birch barks are effective sorbents for cationic dyes; however, the efficiency of dye sorption on both bark sorbents depends on the type of cationic dye. According to the obtained data, beech and birch bark sorbents showed higher sorption efficiency for Basic Red 46 than for Basic Violet 10. The pH correction was a necessary condition for sorption, and the sorption pH value for the cationic dyes Basic Red 46 and Basic Violet 10 was be determined individually for each dye. The most favourable pH value for the sorption of the BR46 dye on the beach and birch bark sorbents was pH = 6, while for the dye BV10, it was pH = 3. The sorption equilibrium time for Basic Red 46 was 300 min and for Basic Violet 10–240 min. The fine fraction of beech bark had the highest sorption capacity for both BR46 (128.45 mg/g dry matter) and BV10 (18.07 mg/g dry matter).

The effect of an acidic environment during the hydrothermal carbonization of sewage sludge on solid and liquid products: The fate of heavy metals, phosphorus and other compounds

The pH of sewage sludge is a crucial factor during the hydrothermal carbonization process that influences the characteristics of the resulting products and migration of certain compounds from the solid to liquid phase. Accordingly, this work is focused on examining the pH impact during the HTC process, in particular, pH equals 2, 3, 4, 5 and 6 on the individual hydrothermally carbonized products generated at 200 °C and 2 h residence time. For this reason, the chemical and physical indicators describing the post-processing liquid and hydrochar were determined. For instance, it was observed that the phosphorus content detected in the liquid, derived at pH2, rose significantly by 80%. Furthermore, decreasing the pH of sewage sludge had a significant impact on the ash content and the calorific value of the hydrochar. Additionally, changes in the specific surface area of hydrochar were noticed: pH = 5 and pH = 6 showed an increase of 20–30%, while for lower pH values a decrease of c.a. 26% was achieved. The distribution of heavy metals between the obtained fractions in the HTC process (solid and liquid) indicated that 92 to almost 100% of the tested heavy metals were transferred to the hydrochar. A significant effect of pH on the distribution between these fractions was observed only for Zn and Ni. For instance, for pH = 2, Zn and Ni in post-processing liquid were 34% and 29%, respectively. In addition, the sequential extraction of heavy metals from hydrochar was also performed in order to identify mobile and non-mobile phases. It was noticed that the acidic environment favours a higher amount of mobile heavy metals in hydrochar. The largest effect was observed for Cd, Pb, Cr and Cu, for which, at pH = 2, their respective amounts in the mobile fraction were 2.7; 3.6; 1.8; 6.2 times higher, compared to the hydrochar without pH correction.

Optimization of the Co-Production between the Rice Husk and the Pulp of the Cashew Apple Produced in the Natural Region of Casamance

Anaerobic digestion or anaerobic digestion is a biological process of degradation of organic matter in an anaerobic environment. It involves the degradation and stabilization of complex organic matter by a consortium of micro-organisms leading to methane-rich biogas that can be used as an alternative energy to fossil fuels. In addition, the use of biogas allows for the preservation of the environment and the sustainable development of rural areas and landlocked regions, as well as the diversification of energy resources, but also contributes to the development of agriculture through the production of organic fertilizer. In 2018, Senegal was ranked as the 15th world exporter of cashew nuts with a production of around 18,000 tons per year according to a study by PADEC (Support Program for the Development of Casamance). Four regions mainly invest in it: Kolda, Ziguinchor, Sédhiou, and Fatick. However, in the natural region of Casamance ( Kolda, Ziguinchor, and Sédhiou), each year, after the cashew nut campaign, more than 342,000 tons of cashew apples, pressed or not, are rejected without any recovery, thus degrading in the environment. In addition, rice is traditionally grown in Casamance and in some Diola circles, it had become one of the criteria of wealth, which explains why it occupied most of the cultivated areas and each year thousands of tons of rice husk are burned for elimination/reduction without any recovery. These immense annual productions of waste, without any recovery, in a context dominated by a deficit in cooking and lighting energy constitutes a form of energy resilience and motivates us to study the co-digestion of the rice husk (with a report of C/N equal to 101.317) on cashew apple pulp (having a C/N ratio of 23.201 ). The study of the co-digestion of rice husk and apple pulp at the laboratory scale with the inoculum reveals, that the co-digestion with pH correction contains 39.40% methane and 51.50% carbon dioxide after 49 days of production and 64.04% methane (CH4) and 25.86% carbon dioxide (CO2) on the 96th day. For co-digestion without adjustment, production stopped on the 49th day with a production of 23.68% methane and 45.65% carbon dioxide.

Unlocking Agronutrient Resources: Sorption Strategies for sugar-energy industry waste

Vinasse and ash from sugarcane bagasse (SCB) are key byproducts in the sugar-energy industry. Vinasse is nutrient-rich but environmentally challenging, while sugarcane bagasse ash (SCBA) offers excellent adsorbent for treating effluents. This work aims to assess the effectiveness of SCBA in removing nitrogen (N) and potassium (K) nutrients from Vinasse. Simulated standard solutions of K2SO4 and (NH4)2HPO4 were used to mimic the nutrient concentrations in Vinasse and optimize experimental parameters such as adsorbent mass and contact time. Kinetic and isotherm models were also applied to elucidate the underlying adsorption mechanisms. Structural, morphological, and thermal analyses revealed the micro-mesoporous and heterogeneous nature of SCBA, primarily composed of SiO2 (quartz and cristobalite). The sorption assessment indicated the ideal conditions involved lower SCBA masses (2.5 g) and 6 h of contact time for the simulated standard solutions. The replicated conditions for Vinasse (at an adjusted sorption time of 24 h) demonstrated nutrient sorption and pH correction of the Vinasse, attributed to the alkaline nature of SCBA. Analysis of the sorption kinetic models for K+ and NH4+ revealed that SCBA interacts diffusively with the environment, not necessarily controlled by adsorption on active sites, indicating non-uniform characteristics. The sorption isotherms for K+ and NH4+ showed the non-linearized Freundlich model was the most suitable, indicating the adsorption sites with varying energy levels and a multilayer sorption process. In conclusion, we successfully demonstrated the sorption of nutrients from Vinasse by SCBA, enhancing the value of these residues and mitigating their environmental impact when used in agricultural applications.

Technical note: Assessment of float pH data quality control methods – a case study in the subpolar northwest Atlantic Ocean

Abstract. Since a pH sensor has become available that is principally suitable for use on demanding autonomous measurement platforms, the marine CO2 system can be observed independently and continuously by Biogeochemical Argo floats. This opens the potential to detect variability and long-term changes in interior ocean inorganic carbon storage and quantify the ocean sink for atmospheric CO2. In combination with a second parameter of the marine CO2 system, pH can be a useful tool to derive the surface ocean CO2 partial pressure (pCO2). The large spatiotemporal variability in the marine CO2 system requires sustained observations to decipher trends and study the impacts of short-term events (e.g., eddies, storms, phytoplankton blooms) but also puts a high emphasis on the quality control of float-based pH measurements. In consequence, a consistent and rigorous quality control procedure is being established to correct sensor offsets or drifts as the interpretation of changes depends on accurate data. By applying current standardized routines of the Argo data management to pH measurements from a pH / O2 float pilot array in the subpolar North Atlantic Ocean, we assess the uncertainties and lack of objective criteria associated with the standardized routines, notably the choice of the reference method for the pH correction (CANYON-B, LIR-pH, ESPER-NN, and ESPER-LIR) and the reference depth for this adjustment. For the studied float array, significant differences ranging between ca. 0.003 pH units and ca. 0.04 pH units are observed between the four reference methods which have been proposed to correct float pH data. Through comparison against discrete and underway pH data from other platforms, an assessment of the adjusted float pH data quality is presented. The results point out noticeable discrepancies near the surface of &gt; 0.004 pH units. In the context of converting surface ocean pH measurements into pCO2 data for the purpose of deriving air–sea CO2 fluxes, we conclude that an accuracy requirement of 0.01 pH units (equivalent to a pCO2 accuracy of 10 µatm as a minimum requirement for potential future inclusion in the Surface Ocean CO2 Atlas, SOCAT, database) is not systematically achieved in the upper ocean. While the limited dataset and regional focus of our study do not allow for firm conclusions, the evidence presented still calls for the inclusion of an additional independent pH reference in the surface ocean in the quality control routines. We therefore propose a way forward to enhance the float pH quality control procedure. In our analysis, the current philosophy of pH data correction against climatological reference data at one single depth in the deep ocean appears insufficient to assure adequate data quality in the surface ocean. Ideally, an additional reference point should be taken at or near the surface where the resulting pCO2 data are of the highest importance to monitor the air–sea exchange of CO2 and would have the potential to very significantly augment the impact of the current observation network.

Is it time to end the use of base deficit for fetal well-being assessment?

Authors have expressed reservations regarding the use of base deficit measured in umbilical artery blood samples to assess fetal well-being during the course of labor and to predict neonatal neurologic morbidity. Despite its integration into clinical practice for more than 50 years, obstetricians and maternal-fetal medicine specialists may not realize that this marker has significant limitations in accurately identifying neonatal metabolic acidosis as a proxy for fetal well-being. In brief, there are 2 large families of base deficit, namely whole blood and extracellular fluid. Both rely on equations that use normal adult acid-base characteristics (pH 7.40 and partial CO2 pressure of 40 mm Hg) that overlook the specificity of the normal in utero acid-base status of pH 7.27 and partial CO2 pressure of 54 mm Hg. In addition, it ignores the unique characteristic of the in utero fetal response to acute hypoxia. The dependence on placental circulation for CO2 elimination may lead to extremely high values (up to 130 to 150 mm Hg) during hypoxic events, a phenomenon that is absent in adults with acute metabolic acidosis who can hyperventilate. The dispute over if to include a correction for high partial CO2 pressure in the bicarbonate estimation, as presented in the Great Trans-Atlantic Debates, remains unresolved. The key constants computed for adult acid-base physiology in the current base deficit algorithms, without accounting for the impact of high partial CO2 pressure or other fetal characteristics of buffering capacity (eg, differences in body water content composition, plasma protein, and hemoglobin attributes), may lead to an overestimation of metabolic acidosis, especially in newborns who are experiencing hypercarbia during the early stages of the hypoxic response. These unrecognized limitations impact the base deficit results and may mislead clinicians on fetal well-being assessments when discussing the management of fetal heart rate monitoring and neonatal outcomes. Based on our arguments, we believe that it is prudent to consider an alternative to base deficit for drawing conclusions regarding fetal well-being during the course of birth management. We propose a marker specifically related to the newborn acid-base physiology--the neonatal eucapnic pH correction. This marker can be added to arterial cord blood gas analysis, and we have described how to interpret it as a marker of neonatal metabolic acidosis.

Water-based technologies for improving water quality at the point of use: A review.

Water safety concerns are increasing tremendously as a result of the rising population and environmental pollution. As a result, viable water treatment approaches need to be designed to meet the water consumption demands of the population, particularly in developing countries. The recent technological advances in water treatment and purification are well articulated in this review. The efficiency of the materials used for purification and their affordability for people living in rural and remote settlements in various parts of the world have been discussed. Water treatment techniques prior to the rapid advancement of science and technology included a variety of strategies such as coagulation/flocculation, filtration, disinfection, flotation and pH correction. The use of nanotechnology in water treatment and purification has modernized the purification process. Therefore, efficient removal of microbes such as bacteria and viruses are exquisitely accomplished. These technologies may include membrane filtration, ultraviolet irradiation, advanced oxidation ion-exchange and biological filtration technologies. Thus, nanotechnology allows for the fabrication of less expensive systems, allowing even low-income people to benefit from it. Most developing countries find these technologies particularly valuable because access to clean and safe water for drinking and residential needs is critical. This is because access to municipal water supplies is also difficult. This article is categorized under: Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials Diagnostic Tools > In Vivo Nanodiagnostics and Imaging.

Investigating the accuracy and comparability of various lime prediction methods for Irish grassland mineral soils

AbstractSoil pH is a foundational element of agronomy, profoundly influencing biological, chemical and physical soil processes. Adjusting soil pH is a paramount factor for enhancing soil health and productivity with far‐reaching environmental benefits. Over time soil naturally tends towards acidity, a process expedited by intensive agriculture practices. To determine the extent of necessary pH corrections, precise soil pH testing is imperative. Various methods including buffer systems, titrations, lime incubations and algorithms considering soil texture are used to assess a soil's lime requirement and each method carries distinct advantages and disadvantages. The Shoemaker–McLean–Pratt (SMP) buffer method is extensively used in Ireland and internationally; however, safety concerns owing to the use of hazardous chemicals required within the method have been highlighted. This study investigates various soil lime requirement tests and compares their performance against a lime incubation study. A proposed alternative to the SMP buffer test for Irish grassland soils is also investigated. Analysis of results obtained indicates that the SMP buffer method demonstrated the highest r2 value of .497 when correlated with lime incubation results, while the calcium hydroxide titration method closely aligns with the SMP buffer method with an r2 value of .816, followed by the modified Mehlich buffer method with an r2 value of .763.

Examining coagulation conditions for the utilization of technical albumen. A preliminary study

Egg processing, a major source of high-value protein for the food industry, is on the rise. However, it generates significant waste. Utilizing egg by-products, especially technical albumen, offers ways to create value-added products. The aim of this study is to examined different coagulation conditions for the utilization of technical albumen. Four types of coagulation were examined. The first type required pH correction using an acid solution (30% citric, lactic, or acetic acid) until the pH ranged from 4.8 to 5.2, followed by thermal coagulation using steam. The second type involved mixing the technical albumen with various percentages of 96% ethanol, ranging from 1% to 10%, followed by coagulation using steam. The third type was a combination of the first two. The precipitates were collected in porous fibre and pressed for 15 minutes at 350 gr/cm2. Citric acid led to grainy, high-yield precipitates; lactic and acetic acid yielded more homogenous precipitates with increased dry matter loss. Only the 7.5% addition of ethanol resulted in relatively high precipitate yield. The combination of pH correction and ethanol addition didn’t enhance yield. Understanding the correlation between the composition of the technical albumen and applied coagulation condition necessitates further analysis.

Cross comparison of alternative diagnostic protocols including substitution to the clinical sample, RNA extraction method and nucleic acid amplification technology for COVID-19 diagnosis.

the gold-standard diagnostic protocol (GSDP) for COVID-19 consists of a nasopharyngeal swab (NPS) sample processed through traditional RNA extraction (TRE) and amplified with retrotranscription quantitative polymerase chain reaction (RT-qPCR). Multiple alternatives were developed to decrease time/cost of GSDP, including alternative clinical samples, RNA extraction methods and nucleic acid amplification. Thus, we carried out a cross comparison of various alternatives methods against GSDP and each other. we tested alternative diagnostic methods using saliva, heat-induced RNA release (HIRR) and a colorimetric retrotranscription loop-mediated isothermal amplification (RT-LAMP) as substitutions to the GSDP. RT-LAMP using NPS processed by TRE showed high sensitivity (96%) and specificity (97%), closely matching GSDP. When saliva was processed by TRE and amplified with both RT-LAMP and RT-qPCR, RT-LAMP yielded high diagnostic parameters (88%-96% sensitivity and 95%-100% specificity) compared to RT-qPCR. Nonetheless, when saliva processed by TRE and detected by RT-LAMP was compared against the GSDP, the resulting diagnostic values for sensitivity (78%) and specificity (87%) were somewhat high but still short of those of the GSDP. Finally, saliva processed with HIRR and detected via RT-LAMP was the simplest and fastest method, but its sensitivity against GSDP was too low (56%) for any clinical application. Also, in this last method, the acidity of a large percentage of saliva samples (9%-22%) affected the pH-sensitive colorimetric indicator used in the test, requiring the exclusion of these acidic samples or an extra step for pH correction. our comparison shows that RT-LAMP technology has diagnostic performance on par with RT-qPCR; likewise, saliva offers the same diagnostic functionality as NPS when subjected to a TRE method. Nonetheless, use of direct saliva after a HIRR and detected with RT-LAMP does not produce an acceptable diagnostic performance.

Development and validation of stability indicating RP-HPLC method for estimation of cyclandelate in bulk drug and capsule dosage form

For the quantification of Cyclandelate (CYL) in bulk medication and capsule dosage form in the presence of degradation products, a quick, accurate, and simple RP-HPLC method was devised. On the Phenomenex Luna C18 (250 mm x 4.6mm, 5 m) column, effective chromatographic separation was accomplished. The separation was made simple by employing the Isocratic elution program with Acetonitrile and buffer pH 3.0 (0.1% Triethylamine in water followed by pH correction with Trifluoroacetic acid) in the ratio of 70:30 (%v/v) at a flow rate of 1.2 mL/min, and an eluent was monitored at 220 nm. The degradation products were found to be isolated from the principal peak after being subjected to force degradation with acid, alkali, peroxide, thermal, and photolytic agents. The technique was linear in the range of 30-200 μg/mL, with a correlation coefficient of 0.9975. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 8.3 μg/mL and 25.1 μg/mL respectively. The presented method was validated for parameters such as system appropriateness, specificity, linearity, accuracy, precision, and robustness. The robustness investigation was part of the validation research as well. The outcomes for every metric are acceptable by ICH standards. Therefore, the method can be considered to be rapid and accurate for high-throughput analysis of this drug even when degradation products are present.

Self-calibrating dual-sensing electrochemical sensors for accurate detection of carbon dioxide in blood.

A paper-based electrochemical dual-function biosensor capable of determining pH and TCO2 was synthesized for the first time using an iridium oxide pH electrode and an all-solid-state ion electrode (ASIE). In the study, to obtain highly reliable results, the biosensor was equipped with a real-time pH correction function before TCO2 measurements. Compared to traditional liquid-filling carbon dioxide detection sensors, the utilization of ferrocene endows our novel sensor with abundant positive sites, and thus greatly improves its performance. Conversely, the introduction of MXene with conductivity close to that of metals reduces electrode resistance, which is beneficial for accelerating the electrochemical reaction of the sensor and reducing LOD. After optimization, the detection range of TCO2 is 0.095 nM-0.66 M, with a detection limit of as low as 0.023 nM. In addition, the sensor was used in real serum sample-spiked recovery experiments and comparison experiments with existing clinical blood gas analyzers, which confirmed the effectiveness of its clinical application. This study provides a method for the rational design of paper-based electrochemical biosensors and a new approach for the clinical detection of blood carbon dioxide.

Accurate ethanol determination in Chinese Baijiu based on red-emitted carbon quantum dots (CQDs) and a simple pH correction.

The quality control of Baijiu is necessary including ethanol content. In this work, red-emitted carbon quantum dots based on p-phenylenediamine (PPD-CQDs) were fabricated for accurate determination of ethanol in Baijiu. The good linear response of PPD-CQDs to ethanol-water solution (E-Ws; 20-80vol%) offered the potential for ethanol determination in practice. However, further application of this procedure to Baijiu resulted in a certain deviation. After excluding interference from most of the ingredients involved, a simple pH correction on Baijiu made application of the process practicable. The red-emission of PPD-CQDs supported analysis of Baijiu with different flavors and ethanol monitoring. Therefore, a quick-response fluorescence method was established for Baijiu ethanol determination; this method can be applied to the many varieties of Chinese Baijiu available and also has potential for use in other alcoholic beverages.

Critical Assessment of pH-Dependent Lipophilicity Profiles of Small Molecules: Which One Should We Use and In Which Cases?

Lipophilicity is a physicochemical property with wide relevance in drug design, computational biology, and food, environmental and medicinal chemistry. Lipophilicity is commonly expressed as thepartition coefficientfor neutral molecules, whereas for molecules with ionizable groups, the distribution coefficient (D) at a given pH is used. The logDpH is usually predicted using a pH correction, while often ignoring the apparent ionic partition [[EQUATION]]. In this work, we studied the impact of [[EQUATION]] on the prediction of both the experimental lipophilicity of small molecules and experimental lipophilicity-based applications and metrics such as lipophilic efficiency (LipE), distribution of spiked drugs in milk products, and pH-dependent partition of water contaminants in synthetic passive samples such as silicones. Our findings show that better predictions are obtained by considering the apparent ionic partition.In this context, we developed machine learning algorithms to determine the cases that [[EQUATION]] should be considered. The results indicate that small, rigid, and unsaturated molecules with logPN close to zero, which present a significant proportion of ionic species in the aqueous phase, were better modeled using the apparent ionic partition [[EQUATION]]). Finally, our findings can serve as guidance to the scientific community working in early-stage drug design, food, and environmental chemistry.

Up-Cycling Grape Pomace through Sourdough Fermentation: Characterization of Phenolic Compounds, Antioxidant Activity, and Anti-Inflammatory Potential.

Despite its appealing composition, because it is rich in fibers and polyphenols, grape pomace, the major by-product of the wine industry, is still discarded or used for feed. This study aimed at exploiting grape pomace functional potential through fermentation with lactic acid bacteria (LAB). A systematic approach, including the progressively optimization of the grape pomace substrate, was used, evaluating pomace percentage, pH, and supplementation of nitrogen and carbon sources. When grape pomace was used at 10%, especially without pH correction, LAB cell viability decreased up to 2 log cycles. Hence, the percentage was lowered to 5 or 2.5% and supplementations with carbon and nitrogen sources, which are crucial for LAB metabolism, were considered aiming at obtaining a proper fermentation of the substrate. The optimization of the substrate enabled the comparison of strains performances and allowed the selection of the best performing strain (Lactiplantibacillus plantarum T0A10). A sourdough, containing 5% of grape pomace and fermented with the selected strain, showed high antioxidant activity on DPPH and ABTS radicals and anti-inflammatory potential on Caco2 cells. The anthocyanins profile of the grape pomace sourdough was also characterized, showing qualitative and quantitative differences before and after fermentation. Overall, the grape pomace sourdough showed promising applications as a functional ingredient in bread making.