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Because of the COVID 19 pandemic, we now utilise hand sanitizer in our daily lives. Hand hygiene has become a legal requirement. Infection control is becoming a requirement. Hand hygiene is widely regarded as the most practical and effective way of infection prevention. Hand sanitizer is thought to have played a significant role in reducing illness transmission to patients. Because it is more cost-effective and efficient. The efficiency of hand sanitizer is totally determined by how it is used. There are two sorts of hand sanitizers on the market. 1) Hand sanitizer with alcohol 2) Hand sanitizer that isn't alcohol-based. Most effective hand sanitizers contain 70 percent to 95 percent alcohol, which has the potential to denature microbial protein and inactivate viruses. The impact of hand sanitizer on human health care is significant, and this review article will provide you with information on several elements of hand sanitizer

AIM AND OBJECTIVE The objective of this study was to monitor the pH stability over a period of 6 months of two-bottle self-etching (SE) primers. MATERIALS AND METHODS Four commercially available two-bottle SE primer solutions, Adhese SE (Ivoclar Vivadent; Schaan, Liechtenstein), Clearfil SE (Kuraray; Tokyo, Japan), Contax Primer (DMG; Hamburg, Germany), and Enabond SE (Micerium; Avegno (Ge), Italy), containing water as the main solvent were selected. The pH values during a 6-month storage period at intermittent temperature were daily measured by means of a microprocessor-based pH/temperature meter and hence recorded, tabulated, and analyzed. RESULTS The mean values of overall pH measurements and standard deviation for Adhese SE, Clearfil SE, Contax Primer, and Enabond SE are, respectively, 1.70 (±0.01), 1.72 (±0.01), 1.20 (±0.01), 1.80 (±0.01). One-way ANOVA did not detect any significant change of the mean pH values of all measurements over time. CONCLUSION The conventional 6-months storage did not affect the pH values of the water-containing primers of two-bottle SE adhesives. CLINICAL SIGNIFICANCE This study provides evidence that conventional storage under adequate conditions did not affect the pH values of the water-containing primers of two-bottle SE adhesives with different monomer formulations. Clinicians may rely on the known pH value of the selected SE adhesive during shelf-life.

Patchouli oil contains patchouli alcohol as the main component which is a tricyclic tertiary alcohol sesquiterpene compound that is insoluble in water. Microemulsion is a droplet dispersion technology that combines an insoluble liquid with another liquid. The role of surfactants in helping the dispersion process of microemulsion formulation is by reducing the interfacial tension. Microemulsion is a supersolvents carrier, so that both hydrophilic and lipophilic can be administered through a microemulsion system. The purpose of this study was to formulate patchouli oil into a stable microemulsion preparation. This research was conducted by making 4 preparations of patchouli oil microemulsion containing 5% (F1), 10% (F2), and 15% (F3) patchouli oil, and microemulsion without patchouli oil (F0). Evaluation of microemulsion preparations includes organoleptic test, pH measurement, density determination, viscosity test, freeze and thaw test, centrifugation test, and particle size analysis. The test results showed that the microemulsion containing 5% patchouli oil had the most stable characteristics compared to other formulas.

The local pH near the surface of a CO₂ reduction electrocatalyst strongly impacts catalytic selectivity and activity. Here, confocal fluorescence microscopy was used to map the electrolyte pH near a copper gas diffusion electrode during CO₂ reduction with micron spatial resolution in three dimensions. We observed that the local pH increased from pH 6.8 to greater than pH 10 as the current density was increased from 0 to 28 mA/cm² in a 100 mM KHCO₃ electrolyte. Variations in the pH across the surface indicate areas of locally increased activity. Within deep trenches of the active layer, the local pH increases as trench width decreases. Computational models confirm these experimental results and also showed that the catalyst found within narrow trenches is more active than that found at the surface of the electrode. This study suggests that the overpotential required to perform selective CO₂ reduction can be reduced by increasing the density of narrow trench regions in the microporous layer.

Purpose Diagnosis and monitoring of laryngopharyngeal reflux (LPR) is a constant challenge in otolaryngological practice, chiefly because there are no specific symptoms characteristic of the disease. In this paper, we present the validation of a simple, 6-level qualitative scale to gauge the clinical findings of LPR. It has been previously published in Polish as the Warsaw Scale. Methods In the study, we enrolled 100 patients with voice problems who had registered in our clinic, and we performed an extended battery of diagnostic tests for LPR, together with 24-h pH monitoring. Results The Warsaw Scale significantly outperformed other instruments in both predicting LPR status and correlating with pH measurements. Moreover, the rating provided by the scale showed a strong association with patient-reported symptoms. Conclusion The data indicate that the Warsaw Scale could be used as an affordable, consistent, and effective diagnostic and monitoring tool for LPR.

Graphene is being used for several innovations and sensor preparation due to its reliability, cost-effectiveness, and availability. Here, a modified Hummer’s method is used for the graphene oxide (GO) electrode preparation with a drop cast for pH measurement. The electrode surface was characterized by several surface-characterizing techniques. A potentiometric gradient of 51 mV/pH at room temperature within the operating pH range of 2–10 was obtained in direct potentiometric measurements. The electrode response as an indicator in mono- and di-protic acid potentiometric titration was similar to a glass electrode but more convenient to handle for daily use.

Notre article présente un inventaire actualisé de la Laîche de Host (Carex hostiana DC.) et de son hybride Carex ×fulva en Aveyron. Leur synonymie est clarifiée et la cartographie des stations aveyronnaises est mise à jour. Quelques stations sont décrites plus précisément à l’aide de relevés phytosociologiques accompagnés de mesures du pH. Des critères d’identification hiérarchisés sont proposés à partir d’une synthèse bibliographique et d’une comparaison biométrique des deux taxons.

From the mid-1800s to the late 1960s, conservation by alum salts (KAl(SO4)2·12H2O—potassium aluminium sulphate), using various recipes, was a common method to prevent shrinkage and to strengthen waterlogged archaeological wooden objects. This method was mainly used in Scandinavia. The alum method appears to have also been applied to highly degraded archaeological waterlogged wood in other countries, for example in the U.S and Germany. Today, many of the archaeological wooden objects treated with alum show extreme deterioration and very low pH, which are attributed to the effects of the alum-treatment. This study investigated the extent of the current levels of chemical degradation in wooden objects conserved with alum salts at different points in time (1880s, 1930s and 1905–13) in order to understand their current condition and whether extent of degradation was in any way related to time of treatment, in an attempt to understand the rate of degradation. It was also an opportunity to compare the chemical state of preservation of alum-treated wood from different collections, as only the Oseberg collection has been intensively studied in this way up until now. Samples from historical wooden objects from the following collections were investigated and compared: the Dejbjerg collection (National Museum of Denmark in Copenhagen); the Oseberg collection (Museum of Cultural History, Oslo, Norway); the Glimmingehus collection (Swedish History Museum, Sweden). Analyses of lignocellulosic polymers and of inorganic compounds were undertaken to evaluate the chemical preservation of the wooden objects. The investigations were performed using a multi-analytical approach which consisted of: pH measurements, analytical pyrolysis (Py-GC/MS), X-ray diffraction (XRD) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM–EDS). It was possible to link the extent of degradation with time, on a general level but we found a great variability in the state of preservation of the wood also within the same collection. It is clear, however that alum-treated wood is more degraded than archaeological wood not treated with alum.

Today, the development of nanomaterials with sensing properties attracts much scientific interest because of the demand for low-cost nontoxic colloidal nanoprobes with high sensitivity and selectivity for various biomedical and environment-related applications. Carbon dots (CDs) are promising candidates for these applications as they demonstrate unique optical properties with intense emissions, biocompatibility, and ease of fabrication. Herein, we developed synthesis protocols to obtain CDs based on o-phenylenediamine with a variety of optical responses depending on additional precursors and changes in the reaction media. The obtained CDs are N-doped (N,S-doped in case of thiourea addition) less than 10 nm spherical particles with emissions observed in the 300–600 nm spectral region depending on their chemical composition. These CDs may act simultaneously as absorptive/fluorescent sensing probes for solvent polarity with ∆S/∆ENT up to 85, for ∆ENT from 0.099 to 1.0 and for pH values in the range of 3.0–8.0, thus opening an opportunity to check the pH in non-pure water or a mixture of solvents. Moreover, CDs preserve their optical properties when embedded in cellulose strips that can be used as sensing probes for fast and easy pH checks. We believe that the resulting dual-purpose sensing nano probes based on CDs will have high demand in various sensing applications.

Background Helicobacter pylori (HP) infection has been implicated in several malignant and nonmalignant conditions. The confirmatory diagnosis of HP requires an endoscopic biopsy, followed by a rapid urease test, culture, and/or histopathologic examination using hemotoxylin and eosin, histochemical stains, or immunohistochemistry against HP. EndoFaster is a novel device that can perform real-time ammonium and pH measurements in gastric juice, allowing a diagnosis of HP during gastroduodenal endoscopy. Goal This study aimed to validate the accuracy of EndoFaster and to compare different histochemical and immunohistochemical techniques for the diagnosis of HP infection. Study Consecutive patients who underwent upper endoscopy at our center were prospectively enrolled. During the endoscopy procedure, gastric juice was aspirated to perform an automatic analysis by EndoFaster and gastric biopsies were taken. Histologic sections were reviewed to assess the histopathologic features. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated for the EndoFaster test, Diff-Quick (DQ), and immunohistochemistry against HP (anti-HP) using Warthin-Starry as the gold standard for HP detection. Results Overall, 80 patients were enrolled. In 19 cases (23,75%), histology was normal. In the remaining cases, varying degrees of inflammation were found. The sensitivity, specificity, positive predictive value, and negative predictive value were 73.33%, 86.00%, 75.86%, and 84.31% for the EndoFaster test using 67 ppm/mL as the positive threshold; 73.33%, 100%, 100%, and 86.21% for DQ; and 79.31%, 88.00%, 79.31%, and 88.00% for anti-HP, respectively. Conclusions The EndoFaster test has good sensitivity and specificity for the diagnosis of HP during the gastroscopy procedure. DQ and anti-HP are excellent alternatives to Warthin-Starry for the detection of HP.

Measurement of pCO2 in highly dynamic coastal zones such as the southern Baltic Sea presents many challenges. In this study, we designed a system to measure pCO2 and then validated it in a series of laboratory and seagoing tests. The fast response time of the system was shown to provide a better resolution of CO2 system gradients. In the open waters of the Baltic Sea, the accuracy of the pCO2 measurements (±1.3 µatm) met the requirements of the ICOS (±2.0 µatm). In the coastal zone, there was less consistency between pCO2, DIC and pH measurements, suggesting the need to redefine the quality assurance and control requirements for the measurement of pCO2 in dynamic regions.

In this work, the development and optimization of a secondary method for pH measurement using a differential potentiometric cell are described. The method was optimized and validated by measurement of three certified primary buffer solutions (CRMs) with nominal pH values of 4.005, 6.865 and 9.180 at 25 °C. The method was applied to assess homogeneity and stability of phosphate buffer solution with nominal pH of 7.000 at 25 °C which will be used as test item in proficiency testing schemes for pH measurement of testing laboratories. The experiments carried out and described in this article proved that this particular design of secondary differential potentiometric cell requires small volume of solutions, is fast, accurate and precise and is suitable for the characterization of secondary buffer solutions and assessment of homogeneity and stability of buffer solutions.

Animal mummies from ancient Egypt are not extensively studied in comparison with human mummies. Dogs mummies were very rare in ancient Egypt, and at the same time were not adequately studied by researchers from conservation point of view. Dog mummy in the present study is dated back to late period (664−333 BC.) and is preserved in the agriculture museum (Egypt). It suffers from different aspects of deterioration such as dirt, holes, wrinkles, missing tissue, accumulated dust, etc. This study aims to evaluate the preservation state of the mummy and explain the deterioration mechanisms to help the conservators later to choose the appropriate materials and methods for the conservation treatment. The analytical techniques used were Auto-Cad, scanning electron microscope (SEM), determination of moisture content, pH measurement, amino acid analysis (AAA), fourier transform infrared (FTIR), portable X-ray fluorescence (XRF), inductively coupled plasma mass spectrometry (ICP-MS) and X-ray diffracion analysis. The results obtained showed different forms of deterioration. Moisture content measurement proved that the mummy was dehydrated. The pH measurement of the mummy components is in acid level. FTIR and amino acid analysis proved that the mummy have been exposed to oxidation process. The analysis by XRF, ICP-MS and XRD proved that bone of the mummy suffered from deterioration.

Summary We present thermodynamic modeling and pH measurements of fluid systems containing acid-gases (e.g., CO2 and H2S), water, and hydrocarbons—replicating the production and shutdown conditions in sour fields—for the purpose of evaluating top-of-line corrosion (TLC) and wellbore integrity and screening/selection of the proper wellbore materials. In particular: An equation of state (EOS) model using Peng-Robinson EOS in combination with the Huron-Vidal (HV) mixing rule for an aqueous subsystem is developed. In the model, subject EOS parameters are calibrated against existing thermodynamic data (saturation data for pure components and solubility data for binary systems) in literature. New in-situ pH measurement data are presented for a model system corresponding to a sour field. It was found that the wellbore can be subjected to pH levels as low as 2.7 with reservoir fluid containing 12 mol% CO2 and 88 mol% CH4 with downhole flowing conditions of 200 bar and 150°C and wellhead shut-in conditions of 300 bar and 4°C, as observed from the experiments. A modeling workflow is developed to estimate pH of the condensed water as a function of temperature and composition of the aqueous phase. The comparison between prediction and experimental measurement shows a very good match between the two (within pH ±0.1). Such studies (pH measurements and prediction) are not available in the literature but play important roles in material screening and assuring wellbore integrity for sour fields. More importantly, sensitivity analysis can be performed to investigate the effects of various factors (such as reservoir temperature/pressure, shutdown conditions, and compositions or extent of souring) on pH prediction. Furthermore, the methodologies developed through this work can also be extended to reservoir facilities, pipelines, sour gas disposal/handling units, and downstream systems such as water utilities, reactor plants, and refineries. The work can also support regulation/licensing for these sour systems.

As a result of the increasing need to study the choice of the assigned value during the inter-laboratory comparisons is becoming more and more relevant. Since the assigned value is a reference point when comparing the results of the participants of the qualification test. Frequently, qualification verification providers face a number of problems when choosing the assigned value. An incomplete analysis of the results of interlaboratory comparisons will lead to an inaccurate assessment of the competence of the laboratory, which contributes to the revocation of the certification of the accreditation of the laboratory participant. This article attempts to provide a complete statistical analysis of the results of interlaboratory comparisons from the beginning to the end of the tour with the content of all statistical analyses recommended in GOST ISO/IEC 17043-2013. The results of interlaboratory comparisons conducted in testing laboratories of Kazakhstan aimed at ensuring metrological traceability of pH measurements in a buffer solution are presented. The reference values of the buffer solution are determined in the state scientific metrological center.

The purpose of this study was to examine the effect of heating on the physical properties of four types of premixed calcium silicate-based root canal sealers. Endoseal MTA, Well-Root ST, EndoSequence BC Sealer, EndoSequence BC Sealer HiFlow, and AH Plus (epoxy resin root canal sealer) were heated at 100°C for 1 min, and changes in setting time, flow, and film thickness were evaluated in accordance with ISO 6876:2012 standards. In addition, pH measurement and scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analyses of the set materials were performed. All root canal sealers heated at 100°C showed significant decreases in setting time and flow, particularly Endoseal MTA. In addition, the film thickness of Endoseal MTA increased significantly after heating at 100°C. The pH and SEM/EDS results were not affected by heating. Heating calcium silicate-based root canal sealers accelerated setting time, decreased flow, and increased film thickness. However, the degree of these changes varied among the products. The present findings indicate that heat-induced changes in the physical properties of calcium silicate-based root canal sealers could adversely affect the quality of warm vertical condensation technique.

The authors reviewed the literature on the most commonly used devices for measuring skin parameters. The instruments were selected to measure: skin elasticity Cutometer® (Courage-Khazaka, Koln, Germany), Reviscometer® RVM600; hydration while using skin properties such as resistance, capacity, conductivity and impedance, the Corneometer CM 820 and CM 825 (Courage & Khazaka, Koln, Germany), Nova DPM 9003 (Nova Technology Corporation, Gloucester, MA, USA), DermaLab® USB Moisture Module (Cortex Technology, Hadsund, Denmark) and Scalar Moisture Checker MY-808S (Scalar Corporation, Japan), to test percutaneous water loss (TEWL) with Tewameter® TM 300 (Courage-Khazaka, Koln, Germany); high-frequency ultrasound scanners Dub®SkinScanner 75 (TPM Company, Lueneburg, Germany), DermaScan® C USB (Cortex Technology, Hadsund, Denmark); for pH measurement Skin-pH-Meter PH 905 (Courage-Khazaka, Koln, Germany), Skin-pH-Meter PH 900 (Courage-Khazaka, Koln, Germany, pH-Meter 1140 (Mettler Toledo, Urdorf, Switzerland); skin sebum is tested by Sebumeter® SM 815 (Courage-Khazaka, Koln, Germany); the Mexameter® MX 18 (Courage-Khazaka, Koln, Germany), CM-2600d Spectrophotometer (Konica Minolta, Tokyo, Japan) and Minolta Chromameter CR-200 (Konica Minolta, Tokyo, Japan. The analysis of measuring devices available on the market introduces the mechanism of their operation and application.

Low salinity water injection has been frequently studied as an enhanced oil recovery process (EOR), mainly due to promising experimental results and because operational needs are not very different from those of the conventional water injection. However, there is no agreement on the mechanisms involved in increasing the displacement of crude oil, except for the effects of wettability changes. Water injection is the oil recovery method mostly used, and considering the characteristics of Colombian oil fields, this study analyses the effect of modifying the ionic composition of the waters involved in the process, starting from the concept of ionic strength (IS) in sandstone type rocks. The experimental plan for this research includes the evaluation of spontaneous imbibition (SI), contact angles, and displacement efficiencies in Berea core plugs. Interfacial tension and pH measurements were also carried out. The initial scenario consists in formation water (FW), with total concentration of 9,800 ppm (TDS) (IS ~ 0.17) and a 27 °API crude oil. Magnesium and Calcium brine were also used in a first approach to assess the effect of the divalent ions. Displacement efficiency tests are performed using IS of 0.17, 0.08, and 0.05, as secondary and tertiary oil recovery and the recovery of oil increases in both scenarios. Spontaneous imbibition curves and contact angle measurements show variations as a function of the ionic strength, validating the displacement efficiencies. Interfacial tension and pH collected data evidence that fluid/fluid interactions occur due to ionic strength modifications. However, as per the conditions of this research, fluid/fluid mechanisms are not as determining as fluid/rock RESUMEN La inyección de agua de baja salinidad ha sido frecuentemente estudiada como un proceso de recobro mejorado (EOR), principalmente debido a resultados experimentales prometedores y dado que las necesidades operacionales no son muy diferentes a las de la inyección de agua convencional. Sin embargo, no existe consenso en los mecanismos por los cuales mejora el desplazamiento de aceite, solo en que está relacionado con un efecto en la humectabilidad. La inyección de agua es el método de recobro más utilizado y, considerando las características de los campos Colombianos, este estudio analiza el efecto de modificar la composición iónica de las aguas involucradas en dicho proceso; partiendo del concepto de fuerza iónica (FI) y para rocas tipo areniscas. El diseño experimental para esta investigación incluye la evaluación de imbibiciones espontáneas (IS), ángulos de contacto y eficiencias de desplazamiento en rocas tipo Berea. También se considera la variación de la tensión interfacial y el pH. El sistema inicial se construyó con agua de formación con concentración total de 9.800 ppm (TDS) (FI ~ 0.17) y crudo de 27 °API. Salmueras de cloruro de Calcio y Magnesio también fueron utilizadas para evaluar el efecto de los iones divalentes. Pruebas de eficiencia de desplazamiento fueron realizadas con agua de fuerza iónica de 0.17, 0.08 y 0.05, en escenarios de recobro secundario y terciario, presentando aumento de la recuperación de aceite en ambos casos. Las mediciones de imbibición espontánea y de ángulos de contacto presentaron variación con la fuerza iónica, validando los resultados de eficiencia de desplazamiento. Las mediciones de tensión interfacial y pH indican interacciones fluido-fluido debidas al cambio en la fuerza iónica, sin embargo; para las condiciones de esta investigación, los mecanismos fluido-fluido no parecen tan determinantes como los fluido-roca.

In the preservation of cultural heritage, the measurement of pH has implications both as a parameter for assessing the state of conservation and as a reference for the preparation and use of aqueou...

Evaluate the efficiency of an autologous whole blood clot (WBC) matrix on diabetic foot ulcers (DFU), and analyse its immune response with near-infrared spectroscopy (NIRS) and pH measurement.Three patients were treated with a WBC. The matrix was produced at the point of care, using a WBC system. A WBC gel was formed and applied onto the wounds. The gel remained in place with primary and secondary dressings.Wound-size reduction was 70% after two applications, 97.6% after three applications, and 90.9% after four applications. The NIRS skeletal muscle oxygen saturation (StO2) increased in all cases.The autologous matrix was efficient in treating DFU. The wound area surface reduced after each application and wound healing was achieved in all cases. More studies are needed to understand the benefits of using a WBC matrix on DFU.Evaluar la eficacia de una matriz autóloga en el tratamiento de úlceras de pie diabético (UPD) de difícil cicatrización, y analizar la respuesta inmune a la aplicación de la matriz con un escáner de infrarrojo cercano (NIRS, por sus siglas en inglés) y un medidor de pH dérmico.Tres pacientes fueron tratados con una matriz de coágulo de sangre completa (WBC, por sus siglas en inglés) autóloga. La matriz se realizó en el punto de atención, mezclando la sangre del paciente con una suspensión coloidal de gluconato de calcio/caolín, e inyectándola en una bandeja de coagulación. Se formó un gel de WBC y se aplicó a las heridas. El gel de WBC se mantuvo en su lugar con apósitos primarios y secundarios.Hubo una reducción del tamaño de las UPD de 70% tras dos aplicaciones, 97,6% después de tres aplicaciones, y 90,9% tras cuatro aplicaciones. El NIRS midió un aumento en la saturación de oxígeno tisular. No hubo reacciones adversas.La matriz autóloga fue eficaz en el tratamiento de las UPD. La superficie de las UPD se redujo después de cada aplicación y se logró el cierre completo de las heridas. Se necesitan más ensayos clínicos para comprender mejor los beneficios de la matriz de WBC en UPD.RedDress Ltd. (Pardes-Hanna, Israel) proporcionó los suministros y materiales del estudio. Bennett Health Inc. ayudó con el desarrollo del protocolo y capacitó al personal sobre la aplicación del producto para coágulos sanguíneos. JA es accionista de Bennett Health Inc. No hubo interés financiero para ninguno de los investigadores o participantes.

Pleural effusion is very common, but an etiologic diagnosis is often difficult. We used three unconventional diagnostic techniques (voltammetric analysis, protein electrophoresis and pH measurement) performed on pleural effusion to do a preliminary distinction between a neoplastic and a non-neoplastic origin. Pleural fluid samples were collected through thoracentesis, thoracoscopy, or post-surgery pleural drainage of 116 patients admitted to acute care wards. Samples were analyzed with the three unconventional techniques: voltammetric analysis using the BIONOTE system, capillary electrophoresis and pH measurement using a potentiometric method. The BIONOTE system is an innovative system that performs a cyclic voltammetric analysis of a biological liquid sample. The final output of the electrochemical analysis is an electrical pattern that represents a fingerprint of the analyzed sample and each sample has a different fingerprint. Data from the three unconventional diagnostic techniques were analyzed using partial least squares discriminant analysis to discriminate neoplastic from non-neoplastic effusions; we also evaluated sensitivity, specificity and percentage of correct classification. The mean age was 68 years (SD: 12); 78 (67.24%) participants were men. Results obtained from all the unconventional techniques employed showed that neoplastic and non-neoplastic pleural effusions were correctly classified in 80.2% of cases, with a sensitivity of 77% and specificity of 83%. The combined use of voltammetric analysis, protein electrophoresis and pH measurement of pleural fluid can easily and quickly distinguish a neoplastic from a non-neoplastic pleural effusion with reliable accuracy and represents an innovative diagnostic approach. In fact, this protocol can be executed in just few minutes directly in the patient's bed and it holds great promise to improve the prognosis and therapeutic chances.

Resumen Las incrustaciones minerales representan un fenómeno recurrente en la industria petrolera que puede ser controlado para evitar problemas operacionales costosos. Para ello se requiere de la aplicación de tratamientos químicos conocidos como inhibidores, los cuales son evaluados tomando en cuenta propiedades como la dureza cálcica o el pH, de manera independiente. Con base en lo expuesto, se desarrolló una metodología que permitió involucrar de forma conjunta distintos parámetros fisicoquímicos para evaluar la eficiencia de inhibidores de incrustaciones de carbonato de calcio; para efectos de esta investigación, se utilizaron dos productos comerciales y un inhibidor natural a base del mucílago extraído de la planta de cayena. En primer lugar, se realizó una esquematización de la metodología evaluativa que se quería desarrollar y que se fundamentó en la unión de tres etapas: valoración mediante la norma NACE TM 0374-2007, que toma en cuenta la dureza cálcica; el índice de saturación de Langelier para determinar la naturaleza incrustante de las aguas y un modelo de medición de pH continúo desarrollado por Zhang, Wu, Li y Zhao. Posteriormente, como parte de la validación de la propuesta, se caracterizaron tres muestras de salmueras sintéticas, y consecutivamente, considerando distintas dosificaciones (55, 100 y 300 ppm) de los productos inhibidores, se aplicó la metodología establecida. Se concluyó que esta nueva propuesta permite evaluar el desempeño de los inhibidores seleccionados en cada una de sus etapas, para así determinar más certeramente la capacidad antiincrustante de los mismos en muestras de salmueras sintéticas a distintas concentraciones, donde se prevea la deposición de incrustaciones minerales de carbonato de calcio (CaCO3). Abstract Mineral scales are a current phenomenon in the oil industry that may be controlled to avoid expensive operational problems. To minimize these problems, it is necessary the application of chemical treatments known as inhibitors which are evaluated considering few parameters such as calcium hardness or pH. As a consequence, a methodology which jointly takes into account physicochemical properties to evaluate efficiency of calcium carbonate scale inhibitors was developed; two commercial products and one organic antiscalant derived from the cayenne mucilage were used. In the first place, an evaluative methodology schematization to be developed was carried out, based on the union of three phases: assessment using the NACE Standard TM 0374-2007, which takes into account calcium hardness; the Langelier saturation index to determine the water scaling nature and a continuous pH measurement model developed by Zhang, Wu, Li and Zhao. Later, to validate the proposal, three samples of synthetic brines were characterized, and consecutively, considering different dosages (55, 100 and 300 ppm) of the inhibitor products, the established methodology was applied. It was concluded that this new proposal allows evaluating the selected inhibitors performance in each of their stages, to accurately determine their antiscaling capacity in synthetic brines samples at different concentrations, where the mineral scales deposition of calcium carbonate (CaCO3) is expected.

Background Oxybrasion is one of the types of microdermabrasion. This method removes a superficial epidermal layer with the use of a stream of 0.9% saline solution and compressed air. Aims The assessment of skin hydration, sebum, pH, TEWL (transepidermal water loss), and pigmentation using oxybrasion. Material and methods The study involved 27 female subjects. Five treatments were performed every 2 weeks using the oxygen microdermabrasion. Measurements of the skin parameters were taken before each treatment and 2 weeks after the last procedure. The measurement points were on the forehead, the cheek, and on the petal of the nose. Results Sebum measurement showed some statistically significant differences between the sebum level on the cheek and the nose after a series of treatments. A higher hydration level was found at all measurement points. There were no statistically significant differences in TEWL parameter. pH measurement showed that the pH value decreased after each of the procedures. Most of the pigmentation measurements differed in a statistically significant way. Conclusion Results of the study indicate that the oxybrasion treatments increase the skin hydration and they have a significant influence on the decrease of the skin hydrolipid coat and pH.

Ethiopian soil affected by strong acidity accounts for about 28% of the entire country and 43% of the total cultivated land. Soil acidity is expanding in scope and magnitude. To tackle the problem, lime addition is one of the solutions. The lack of soil specific lime recommendation method(s) to amend the increasing acidification problem has been one of the challenges to boost crop production. Therefore, a greenhouse experiment to select best-fit LR method(s) and calibrate on Luvisol was conducted. Different LR methods were evaluated to find out which of these methods most accurately predicted the LR in comparison with reference CaCO3‐incubation. The initial LR dose for incubation experiment was calculated using Shoemaker, Mc lean and Pratt (SMP) method to achieve a target pH of 6.0, followed by progressive incremental addition of lime. Then, the soil was incubated with different doses of CaCO3 for a period of five weeks to achieve different target pHs. The results of incubation were compared with the buffered and unbuffered LR methods. The CaCO3 incubation pH measurement results showed an increasing trend with an increasing amount of lime added. The LR prediction ability of exchangeable acidity and single addition Ca (OH)2 were the least of all the methods tested for Luvisol, when compared to the reference method. Adams Evan and modified Mehlich LR predication are next to incubation in LR prediction for Luvisol. However, more researches that are detailed are needed to verify and synchronize the greenhouse results with field experiment in different agro ecologies to increase nutrient supply to the plant, water percolation and crop production. Key words: Acidity, luvisols, lime, lime requirement, Shoemaker, Mc lean and Pratt (SMP), modified Mehlich.

This study aims to find out whether DFD (Dark, Firm, and Dry) and PSE (Pale, Soft, and Exsudative) happen/ occur to Bali Cattle Carcas slayed in Anggoeya Animal Slaugtherhouse in Kendari City. This study is useful to give information about the meats’ DFD and PSE cases and carcas quality at Anggoeya Slaugtherhouse in Kendari City. The sample of this study are 6 bulls and 6 cows taken from slaugtherhouse in Kendari City. The obtained data was, then, analyzed descriptively based on the mean and deviation standard (χ ± SD).The variables observed in this studyincludes PH measurement for 1 – 6 hours after slashing, color, loss of mass, texture, hardness, and humidity. The meats were found to be around normal PH 5.55 – 5.73. Based on the color score AUS_MEAT Colour, the color of the meats were around the score of 4 – 5, loss of mass were around 30,64 – 43,28%. Based on panelist judgement, most of the meats texture were scored 3 or were in moderate level. Most of the meats’ elasticity were scored 3 or were rather soft, while most of the meats’ humidity were scored 3 or moderate (62.50%). On the meats produced by the Animals Slaugtherhouse in Kendari City, no changes to DFD (Dark, Firm, and Dry) or PSE (Pale, Soft and Exudative) was found.

Liquid chemical fertilizers are widely used in modern agriculture. The pH values of these fertilizers are important in terms of their effectiveness in the field application and their effect on the soil-water pH balance. Therefore, it is necessary to measure the pH and other properties of liquid fertilizers with fast, practical and inexpensive methods. With the advancing technology, pH value has been started to measure more accurately and efficiently with the help of low-cost devices. In this study, a low-cost pH meter was developed using a low-cost pH sensor, an Arduino UNO R3 microcontroller board, and a software written in the C/C++ programming language. The developed pH meter was used to measure the pH values of liquid chemical fertilizers. Close variations were observed between the values obtained from it and the values measured by an accredited, laboratory-type pH meter. According to the pH measurements of the two pH meters, R2 ranged 88.1% to 99.3%, average error range 0.14 to 0.28, and average error percentage ranged 1.56% to 6.81% for three different types of liquid fertilizers. In light of these results, it was shown that the developed low-cost pH meter can be useful for practical pH measurement applications.

The objective of the study was to evaluate, for the first time, the qualitative, objective and subjective characteristics of the carcass and meat of the Beni-Guil sheep breed, originating in Eastern Morocco. The study was conducted with 105 ewes and ewe lambs with a mean age of 21.5 months (8–36 months), and a mean weight of 32.55 kg. pH measurements were taken one hour and 24 hours after slaughter. The mean values obtained were 6.76 and 5.78, respectively. The mean hot (HCW) and cold (CCW) carcass weights and corresponding yields were 15.82 kg (48.6%) and 15.52 kg (47.7%), respectively. Shrinkage loss was 1.9%. Linear measurements showed that the Beni-Guil had a mean carcass length (K) and width (G) of 63.7 and 17.3 cm, respectively, with a carcass compactness index 1 (G/K) and 2 (CCW/K) of 0.27 and 243.60 g/cm, respectively. Finally, according to the EUROP sheep carcass classification grid, the carcasses examined showed conformations between fairly good (O) and good (R), a bright red color, a firm white fat cover, and a fatness score of 3.42. The results highlighted the characteristics of the Beni-Guil ewe carcass, which are sought by professionals and consumers.

The Main Hall of the Fengguo monastery in Yixian county, Liaoning province, China, is the best preserved and largest wooden Buddhist structure, typical of the Liao dynasty style, in China. However, some degradation to the timber frame of the Main Hall has been noted, and this is causing concern in terms of the long-term preservation of the structure. In this study, wooden pillars showing the degradation phenomena of whitening, for areas in contact with the stone floor, and extensive surface damage at higher locations(mostly above 1 m) have been examined. Samples taken from wooden pillar surfaces were analyzed using X-ray powder diffraction, Fourier-transform infrared spectroscopy(FTIR), ion chromatography, and pH measurements. With respect to the whitening phenomenon, we found inorganic calcium precipitates and oxalate ions, along with higher pH values. These symptoms indicated that chemical changes were taking place in response to alkaline conditions, suggesting that alkaline mixtures with calcium content in the foundations may be responsible. Regarding the upper surface-damaged areas, no valid evidence for chemical degradation was found using FTIR analysis, while damaged areas exhibited the presence of more bat guano-related materials than which were apparent in undamaged areas. The occurrence of this surface-damaged phenomenon has therefore been attributed to physical damage caused by bat activity over long periods of time.

PurposeThis study aims to determine the probiotic potential ofLactobacillus rhamnosusGR-1 from Fiti sachets, in four widely consumed pulses, namely, black-eyed pea, pigeon pea, kabuli chickpea and desi chickpea. The secondary objective was to determine the viability of the fermented pulses during 21 days of storage at 4°C.Design/methodology/approachEach pulse sample was mixed with a Fiti sachet (one gram of freeze-dried consortium ofLactobacillus rhamnosusGR-1 andStreptococcus thermophilusC106) and fermented for up to 120 h. To assess the samples’ storage potential, they were refrigerated at 4°C for 21 days. Microbial enumerations and pH measurements were collected during fermentation and storage to determine the viability and fermentation potential ofLactobacillus rhamnosusGR-1 and Fiti, respectively.FindingsThere was a significant (p= 0.01) difference in mean microbial counts in all pulse samples throughout fermentation. At 24 h of fermentation, the mean bacterial count ofLactobacillus rhamnosusGR-1 in black-eyed pea, pigeon pea, kabuli chickpea and desi chickpea were 1.32 × 109 ± 0.11, 1.01 × 109 ± 0.16, 1.52 × 109 ± 0.14 and 0.80 × 109 ± 0.05 CFU/mL, respectively. Fermentation of pigeon pea, kabuli chickpea and desi chickpea at 48 h yielded the highest bacterial count forLactobacillus rhamnosusGR-1 while black-eyed pea reached its highest bacterial count at 72 h of fermentation. The bacterial concentration of all pulse samples remained at around 109CFU/mL during the refrigeration period of 21 days at 4°C. Furthermore, the pH of all pulse samples were below 4.6 during both fermentation and refrigerated storage.Originality/valueSince 2004, the Fiti initiative has economically empowered hundreds of women in East Africa by teaching them how to produce and sell probiotic yogurt containingLactobacillus rhamnosusGR-1. As a result, Fiti probiotic yogurt was made accessible to vulnerable populations in East Africa who face malnutrition, infectious diseases and environmental toxins. Because of recent climatic changes, milk has become more expensive and inaccessible for local communities. Furthermore, this study found that black-eyed pea, pigeon pea, kabuli chickpea and desi chickpea can be viable and non-diary probiotic alternatives to the Fiti probiotic yogurt in Eastern Africa. This is also the first study of its kind to provide preliminary evidence showing pulses as non-dairy alternatives to Fiti probiotic yogurt.

Potentiometric pH probes remain the gold standard for the detection of pH but are not sufficiently sensitive to reliably detect ocean acidification at adequate frequency. Here, potentiometric probes are made dramatically more sensitive by placing a capacitive electronic component in series to the pH probe while imposing a constant potential over the measurement circuit. Each sample change now triggers a capacitive current transient that is easily identified between the two equilibrium states, and is integrated to reveal the accumulated charge. This affords dramatically higher precision than with traditional potentiometric probes. pH changes down to 0.001 pH units are easily distinguished in buffer and seawater samples, at a precision (standard deviation) of 28 μpH and 67 μpH, respectively, orders of magnitude better than what is possible with potentiometric pH probes.

Changes in maple wood’s pH and color (Acer pseudoplatanus) were evaluated before and after thermal treatment process with saturated water steam. Maple wood was thermally treated at temperatures: tI = 105 ± 2.5 °C, tII = 125 ± 2.5 °C, and tIII = 135 ± 2.5 °C for τ ≤ 12 hours. Direct pH measurement of maple wood with a moisture content above the fiber saturation point (FSP) was performed using a pH-meter SI 600 with a Lance FET + H puncture probe. The polynomial dependence of pH and total color difference ∆E* on temperature t time τ was calculated by statistical processing of measured results. The correlation between the total color difference ∆E* of maple wood in the process of thermal color modification and the pH value is expressed y the equation: ∆E* = 4.5516∙(pH)2 – 48.405∙(pH) + 134.35. This dependence is a suitable tool for assessing the achieved color change based on the change of wood pH in the technological process.

pH Meter is a device used to express the level of acidity or basicity possessed by a substance or solution. Normal pH has a value of 7 while the pH value> 7 indicates that the substance has alkaline properties while the pH value

The storage shelf life of brews has become progressively important in recent years for the beverage’s manufacturers. The objectives of this study were to investigate the proximate composition and mineral contents of the proposed roasted date seeds powders, to model the kinetic changes in the properties of the brews during storage and to establish a predictive model for forecasting the shelf life by integration of consumer acceptability and quality attributes of the brews. Foremost, the chemical composition and mineral content analysis of both full fat and low-fat powders were investigated using the standard methods. The brews were prepared using hot water and then stored up to 30 days at 4, 25, 38 °C. Samples of brews were taken initially and after 2, 4, 6, 12, 18, 24 and 30 days for conducting pH measurement and sensory evaluation. Kinetic modelling for the properties were conducted by applying the nonlinear regression technique. Besides, the shelf life of the brews was predicted by integration of the acceptability and quality indicators. The results revealed that pH, H3O+ and sensory attributes of the brews were significantly influenced by the storage conditions. Descriptive models have been developed for describing the different properties and the shelf life of brews. In addition, the brews were microbiologically stable during the predicted shelf life period under different storage temperatures and times.

It is known that there are many ways to manage food waste, however, no specific work has ever been reported on the easiness and economics of treatment mainly at the source. This study hopes to fulfill the gap by constructing a novel waste bin layered with plastic that can continuously accommodate and decompose food waste produced at the source. After several months of use, the bin has been found to be effective and no foul odor has been detected at least 1 ft away. In addition, produced leachate has been found to be nontoxic and can be used to water plants as evidenced by the pH measurements. Furthermore, introduction of additional features such as covering the bin with a painted cloth and putting a chimney on its top has been observed to enhance the performance.

Background: The appropriateness of the wound bed for autograft transplantation is routinely evaluated based on the surgeon's judgment, which might not be reliable in some situations. Therefore, this study was designed to evaluate the association between wound pH, wound temperature, and wound culture results with autograft taking. Materials and Methods: In this prospective, cross-sectional study, the body core temperature, wound pH, and local wound temperature at the beginning of operation and after burn wound excision were measured in 50 patients with burn wounds. Swab culture specimen was obtained from the burn wound after dressing removal and after the completion of wound excision. Autograft taking was evaluated on days 3 and 7 postoperative. Results: There was a statistically significant reverse association between autograft taking on day 3 and wound pH at the beginning of operation (P = 0.016). Besides, there was a statistically significant association between core body temperature and autograft taking on days 3 (P = 0.035) and 7 (P = 0.002). However, there was no significant association between local wound temperature and autograft taking. A positive result for wound culture after excision, even when the colony count was

Introduction/aim: Levo-pantoprazole, the S-enantiomer of pantoprazole, is a proton pump inhibitor that has been shown in animal studies to be faster and stronger than its racemic formulation. There are no studies on humans and therefore our aim was to evaluate the effects of levo-pantoprazole versus racemic pantoprazole on intragastric pH. Materials and methods: A randomized controlled study was conducted on patients with erosive gastroesophageal reflux disease that were given 20 mg of levo-pantoprazole (n = 15) versus 40 mg of racemic pantoprazole (n = 15) for 7 days. Baseline and end-of-treatment symptom evaluation and intragastric pH measurement were carried out. Results: There were no differences between the groups in the baseline evaluations. From 40 to 115 min after the first dose of levo-pantoprazole, the mean intragastric pH was higher, compared with that of racemic pantoprazole (p < 0.05). After one week, levo-pantoprazole and racemic pantoprazole significantly reduced intragastric acid production and its esophageal exposure (p < 0.05). Even though there was no statistically significant difference, a larger number of patients that received levo-pantoprazole stated that their heartburn improved within the first 3 days. Conclusions: The S-enantiomer of pantoprazole (levo-pantoprazole) had a faster and stronger effect with respect to acid suppression, compared with its racemic formulation. Although the effect on symptoms was faster with levo-pantoprazole, occurring within the first days of treatment, it was equivalent to that of the racemate at one week of treatment. Resumen: Introducción/objetivo: El S-enantiómero del pantoprazol, el levopantoprazol, es un inhibidor de la bomba de protones que en estudios animales ha mostrado ser más rápido y potente que su formulación racémica. Sin embargo, no existen estudios en humanos por lo que nuestro objetivo fue evaluar los efectos sobre el pH intragástrico de levopantoprazol versus de pantoprazol racémico. Material y métodos: Estudio aleatorizado controlado en pacientes con enfermedad por reflujo gastroesofágico erosivo a quienes se les administró 20 mg de levopantoprazol (n=15) versus 40 mg de pantoprazol racémico (n=15) durante 7 días. De forma basal y al final del tratamiento se realizó evaluación sintomática y medición del pH intragástrico. Resultados: No hubo diferencias entre los grupos en las evaluaciones realizadas de forma basal. A partir de los 40 minutos y hasta los 115 minutos posterior a la primera dosis de levopantoprazol el pH intragástrico promedio fue mayor en comparación que el pantoprazol racémico (p

Nasogastric tube is widely used in intensive care units. The complications of misplacement are rare but very dangerous for critically ill patients. Accurate localization of the position of the tip of nasogastric tube can effectively decrease complications and ensure the safety of critically ill patients. There are various methods that can be used to verify the location of the nasogastric tube such as radiography, PH measurement, electromagnetic navigator and ultrasound. However, there is a lack of general consensus regarding a standard method. In this review, we found that the accuracy of nasogastric tube placement can be greatly improved by visual technology such as X-ray, sonography and electromagnetic navigator. However, visual technology has not been widely used to locate the tip of nasogastric tube in critically ill patients. Best practice guidelines based on the available knowledge and evidence of current methods are necessary to increase the accuracy placement of nasogastric tube. It is envisioned that development of visual technologies will determine a new standard of care for verification of placement of nasogastric tube.

An optical pH sensor that enables the non-destructive measurement of acetic acid and its distribution in a photovoltaic module during damp heat (DH) testing is reported. The sensor was fabricated by impregnating a solution of a pH-sensitive fluorescent dye into a fluororesin membrane filter, which was then dried. While conducting the DH test, fluorescence spectra from 20 pH sensors were periodically recorded and converted into pH values using a predetermined calibration curve. As a result, we succeeded in measuring changes in pH with a DH test time of up to 2000 h, and it was possible to obtain information on the pH distribution in the module. We also confirmed no change in pH in a module with a silicone encapsulant free from acetic acid, and revealed that the sensor that we developed does not respond to moisture and heat, but only to acetic acid.

This communication is focused on the synthesis, characterization and experimental proof of the mechanism of antimicrobial activity of powders from the molybdenum-tungsten-oxygen (Mo-W-O) system. Materials with a discrete ratio of Mo/W ranging from 100% MoO

In aqueous magnesium air batteries, the influence of the electrochemical behavior on pH of the electrolyte has not been investigated yet, which has a critical effect on the cell performance. We have monitored the evolution of the pH at various discharge current densities in situ in the Mg-air primary cells, which produce sparingly soluble magnesium hydroxide (Mg(OH)$_{2}$). These experiments show the temporal evolution of the pH of the electrolyte in the cell discharge, depending on the current density. The pH first increases rapidly to a maximum of pH 11 and then drops down slowly to the equilibrium at pH 10.7. At the peak pH oversaturation of Mg(OH)$_{2}$ is paramount, leading to the precipitation which balances the Mg(OH)$_{2}$ concentration in the electrolyte. This precipitation process coats both cathode and anode which leads to a decrease in cell efficiency and voltage. The results show that the cell design of Mg-air batteries is important for their lifetime and cell performance. The performance of the aqueous magnesium cell is increased several folds when the design is changed to a simple electrolyte flow cell.

Stomach cancer is a global health issue because of its incidence and mortality rates worldwide. We developed a near-infrared (NIR) emissive ratiometric two-photon (TP) probe (HCC1) for the quantita...

5th International Symposium on the Ocean in a High CO2 World, 13-16 September 2022, Lima, Perú, The pH spectrophotometric method is the gold standard to measure pH in the ocean and detect ocean acidification trends due to the anthropogenic carbon uptake from the atmosphere into the ocean. The pH method has an accuracy of about 0.003 and a precision of about 0.0004 pH units. The method has evolved since the 1990s when defined using manual approaches and unpurified dyes to currently automated methods using expensive and cumbersome to obtain purified dyes. From a collection of about 300 paired measurements of unpurified and purified pH measurements along with DIC and TA from natural samples in the Eastern North Atlantic and Mediterranean Sea we find that contrary to expected, unpurified and purified pH measurements calculated with the proper corresponding functions agree to within 0.003 pH units for waters with pH >7.95, while waters with lower pH, calculated unpurified pH is higher than purified pH. Applying the purposed correction from unpur to pur pH as explained in the literature is not straight forward, the community risks for an incoherence in the pH time series. Clearly, we need a definition and evaluation of the unpur to pur correction on real seawater samples by different labs, and look for a consensus agreement on seawater pH definition (scales!, ionic model), metrology, and on the Standard Operational Procedure, where loose issues are still present

The dichromatism of Bromophenol blue (BPB) was investigated by varying its concentration in the absence and presence of surfactant. A model of the indicator behavior was carried out, justifying the experimental shapes of the sigmoidal profiles of the hue (H) coordinate. The model applied to the solution was compared with the performance of colorimetric sensor arrays (CSAs) with increasing BPB concentrations. The H shape and the prediction errors of the CSAs were very similar to those predicted. The experimental results enable the changing of the slope of the calibration profiles, at will, by varying only the BPB concentration.

MgO nanoparticles (NPs) are widely used in diverse areas ranging from catalysis to sensing. Besides this, there is a lack of information regarding their toxicity on fauna and flora. The venture of this work is to evaluate the toxicity behavior and pH-sensing performance of l-lysine-modified MgO (Ly-MgO) NPs synthesized by the green approach using the clove (Syzygium aromaticum) bud extract. The detailed investigations revealed that concentration plays an important role toward in vitro toxicity of Ly-MgO NPs. The Ly-MgO NPs showed 105% biocompatibility toward Vigna radiata (green gram) seeds at 100 ppm concentration. Zero inhibition on microbial growth was observed toward two bacterial strains. Further, pH-sensing strips based on these Ly-MgO nanostructures were developed to test pH-sensing performance at pH values ranging from 2.0 to 13.0. The repeatability as well as recyclability of the prepared pH strips was also analyzed. Nanobased pH paper strips based on Ly-MgO NPs provide a simple, reliable, nontoxic, and affordable method for pH measurements.

This paper proposed an optical pH measurement system developed to measure the changes of pH levels based on colorimetric reactions with phenol red reagent. The optical sensing was achieved through the implementation of a pair of light emitting diode (LED) and photodiode. The detection mechanism was based on different absorbance of light intensity at pH values of 2.36, 8.32, 9.08 and 12.83. The data processing method was carried out using LabVIEW software and interfaced with NI USB DAQ 6008. The measured voltage showed a good correlation in relation to the pH level with R2 equals to 0.9624. This relationship was used as a calibration curve in the final system testing. The final measurement of pH showed a good agreement between the actual and measured values with an error of less than 5%, thus indicating the reliability of the proposed system.

Information on marine CO2 system variability has been limited along the Inside Passage of the Pacific Northwest coast of North America despite the region’s rich biodiversity, abundant fisheries, and developing aquaculture industry. Beginning in 2017, the Alaska Marine Highway System M/V Columbia has served as a platform for surface underway data collection while conducting twice weekly ~1600-km transits between Bellingham, Washington and Skagway, Alaska. This dataset allowed for the assessment of marine CO2 system patterns along the Inside Passage, including quantification of the relative importance of key drivers in shaping pCO2 variability. Surface water pH and aragonite saturation state (Ωarag) were determined using the pCO2 data with alkalinity from a regional salinity-based relationship, which was evaluated with discrete seawater samples and underway pH measurements. Low pH and corrosive (Ωarag < 1) Ωarag conditions were seen during winter and in persistent tidal mixing zones, and corrosive Ωarag values were also seen in areas that receive significant glacial melt in summer. The time-of-detection was computed and revealed that tidal mixing zones may be sentinel observing sites with relatively short time spans of observation needed to capture secular trends in seawater pCO2 equivalent to the contemporary atmospheric CO2 increase. Finally, anthropogenic CO2 was estimated and showed notable time and space variability. We theoretically considered the change in hydrogen ion concentration ([H+]), pH, and Ωarag over the industrial era and to an atmospheric pCO2 level consistent with a 1.5 °C warmer climate and revealed greater changes in [H+] and pH in winter as opposed to larger Ωarag change in summer. In addition, the contemporary acidification signal everywhere along the Inside Passage exceeded the global average, with Johnstone Strait and the Salish Sea standing out as potential bellwethers for biological OA impacts. In theory, roughly half the acidification signal experienced thus far over the industrial era may be expected over the coming 15 years with an atmospheric CO2 trajectory that continues to be shaped by fossil-fuel development.

Extracellular pH (pHe) is an important chemical factor in many cellular processes and disease pathologies. The routine sampling of pHe in vitro could lead to innovative advances in therapeutics. To this end, we have fabricated a novel gold-coated polymer mesh, which facilitates the real-time measurement of pHe via surface-enhanced Raman scattering (SERS). In this proof of concept study, we apply our SERS sensor to measure metabolically induced changes in the pHe of carcinoma-derived cell line HepG2/C3A. We demonstrate that gold-coated polyurethane electrospun nanofibers (AuNF) have strong and reproducible SERS spectra of surface-adsorbed analytes. By functionalizing AuNF with pH-responsive reporter 4-mercaptobenzoic acid (MBA), we have developed an accurate pH SERS sensor for the extracellular microenvironment. We cultured HepG2/C3A on the surface of MBA-AuNF and measured an acidic shift in pHe at the cell-fiber interface. Following exposure to staurosporine, an apoptosis-inducing drug, we observed changes in the HepG2/C3A cellular morphology indicative of controlled cell death, and detected an increase in the pHe of HepG2/C3A. These results demonstrate how subtle changes in pHe, induced by the metabolic activity of cells, can be measured with our novel SERS sensor MBA-AuNF. The excellent pH measurement performance of MBA-AuNF provides a unique platform to study extracellular pH on the microscale and will help to deepen our understanding of pHe in disease pathology.