Increase In Hydrogen Ion Concentration Research Articles

Long-term trends of pH, alkalinity, and hydrogen ion concentration in an upwelling-dominated coastal ecosystem: Ría de Vigo, NW Spain

The present study focuses on the Ría de Vigo (NW Spain), a coastal embayment influenced by the Canary Current Upwelling System, which is among the world’s significant Eastern Boundary Upwelling Ecosystems. The research assesses historical changes in the marine carbonate system by generating 25-year weekly time series at six stations . Assessing ocean acidification in the region is complex due to diverse factors influencing coastal carbon dynamics, making predictions more challenging. To capture the specific dynamics in Ría de Vigo, ensembles of Neural Networks were applied. These networks were trained with a data set obtained in several oceanographic cruises, in order to retrieve pH, hydrogen ion concentration and alkalinity, achieving a root mean square error of 0.0272 pH units, 0.588 nmol kg-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hbox {kg}^{-1}$$\\end{document}, and 10.6 μ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\upmu$$\\end{document}mol kg-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hbox {kg}^{-1}$$\\end{document}, respectively. Subsequently, time series of the selected variables were generated, applying data of predictors measured at the aforementioned stations . An increase in normalized alkalinity was observed for all stations, except in the surface layer at the innermost location. A decrease in pH and an increase in hydrogen ion concentration were observed for all points, with trends that exceed reported rates of ocean acidification in the open ocean.

A STUDY ON CORRELATION OF ACIDEMIA WITH PATIENTS 30 DAYS MORTALITY THOSE PRESENTING TO EMERGENCY DEPARTMENT OF A TERTIARY HOSPITAL

Introduction: Acidosis is a process causing increased acidity in the blood and other body tissues (i.e., an increase in hydrogen ion concentration). If not further qualied, it usually refers to acidity of the blood plasma Acidemia is said to occur when arterial pH falls below 7.35 , while its counterpart (alkalemia) occurs at a pH over 7.45. Arterial blood gas analysis and other tests are required to separate the main causes.Aims: To nd out correlation between different grades of Acidemia with 30 day mortality of patient diagnosed as academic in emergency department Materials and method: This was a single center observational, retrospective cohort study from tertiary care hospital in Kolkata, India from January 2021 – January – 2022. All Patients were presenting with signs of Acidemia in Emergency Department. Age >18 years, Blood gas analysis, Done in ED and pH ≤ 7.34 were included in this study. Result: In mortality, 33(32.4%) patients were in <7.0 PH group, 31(30.4%) patients were in 7.0-7.10 PH group, 23 (22.5%) patients were in 7.11-7.20 PH group and 15 (14.7%) patients were in 7.21-7.34 PH group. Association of PH group with Mortality was statistically signicant (p<0.0001). In without Mortality, the mean Age (mean± s.d.) of patients was 57.0268 ±9.2811. In with Mortality, the mean Age (mean± s.d.) of patients was 56.2549±9.0758. Distribution of mean Age with Mortality was not statistically signicant (p=0.4506). In without Mortality, the mean PH (mean± s.d.) of patients was 7.1898 ±.1189. In with Mortality, the mean PH (mean± s.d.) of patients was 6.9708 ±.2907. Distribution of mean PH with Mortality was statistically signicant (p<0.0001). In without Mortality, the mean Hospital Stay (mean± s.d.) of patients was 14.1512 ±5.5302. In with Mortality, the mean Hospital Stay (mean± s.d.) of patients was 7.4804 ±6.1010. Distribution of mean Hospital Stay with Mortality was statistically signicant (p<0.0001). Conclusion: Patients presenting in emergency with low PH (acidemia) require immediate management and hospitalization for better outcome.

Kinetics and Mechanism of Oxidation of Chloramphenicol by 12-Tungstocobaltate(III) in an Acidic Medium

The oxidation of Chloramphenicol (CAP) by Keggin-type 12-tungstocobaltate(III) anion was investigated spectrophotometrically under pseudo-first-order conditions in perchloric acid at 303K.  Under these reaction conditions, CAP exists in unprotonated form. The reaction was found to proceed via the formation of a weak complex between the reactants. A direct electron transfer from CAP to the 12-tungstocobaltate(III) anion generated a 3-(4-nitrophenyl)-2,2-dichloroacetamido-1-propanol-3-oxy free radical in the rate-determining step. This free radical was further oxidised to give 4-nitrobenzaldehyde, dichloroacetic acid, and glycoaldehyde. The rate constant increased with an increase in concentration of the substrate. The reaction rate remained constant with an increase in hydrogen ion concentration, and was independent of the ionic strength. The products of the reaction were confirmed by LC-MS, FT-IR and 1H NMR spectroscopy. The thermodynamic parameters were evaluated by temperature variation kinetic data. A detailed mechanism and rate equation are proposed for the reaction.

Kinetics and Mechanism of Oxidation of Glutahione by Waugh‐Type Enneamolybdomanganate(IV) in Aqueous Perchloric Acid

AbstractThe reaction between enneamolybdomanganate(IV) and glutathione is studied under second‐order conditions in aqueous perchloric acid. The reaction first‐order in both the reactants and initiated through formation of a precursor complex. Protonated forms of both the reactants are found to be active as evidenced by the accelerating effect of increasing hydrogen ion concentration effect. The second step of the reaction is the slow decomposition of the complex leading to the formation of hydroxyl intermediate. The final product glutathione disulfide is formed in the fast third step as a result of reaction of intermediate with another glutathione cation.

Electrocatalitic Detection of Hydrazine Using Chemically Modified Electrodes with Cobalt Pentacyanonitrosylferrate Adsorbed on the 3–Aminopropylsilica Surface

Cobalt pentacyanonitrosylferrate on the aminopropylsilica silica gel surface (SiCoNP) was previously prepared following two steps. The electrochemical behavior of SiCoNP modified electrode showed two redox couples, the first and second redox couples were observed at anodic potential (Epa)1 = 0.36 and 0.60 V vs. Ag/AgCl attributed to the oxidation of Co(II) to Co(III) and Fe(II)(CN)5NO/Fe(III)(CN)5NO, respectively. The modified carbon paste electrode with SiCoNP was tested in the hydrazine electrooxidation. In the hydrazine electrooxidation, the H+ release was observed and the two metal centers are involved in this process. The proposed mechanism has been described and based on studies of the effect of hydrogen ion concentration in the redox process of bivalent compound formed. Thus a large increase in hydrogen ion concentration promotes the formation of an intermediate electroactive species with an anodic peak at 0.56 V. The nature of this species is not well established but may be related to protonation of cyanide or NO groups present. The modified graphite paste electrode presented a limit of detection of 2.38×10-4 mol L-1 and amperometric sensitivity of 1.37×10-6 A.mol-1.L.

Multiple Acid Sensors Control Helicobacter pylori Colonization of the Stomach

Helicobacter pylori’s ability to respond to environmental cues in the stomach is integral to its survival. By directly visualizing H. pylori swimming behavior when encountering a microscopic gradient consisting of the repellent acid and attractant urea, we found that H. pylori is able to simultaneously detect both signals, and its response depends on the magnitudes of the individual signals. By testing for the bacteria’s response to a pure acid gradient, we discovered that the chemoreceptors TlpA and TlpD are each independent acid sensors. They enable H. pylori to respond to and escape from increases in hydrogen ion concentration near 100 nanomolar. TlpD also mediates attraction to basic pH, a response dampened by another chemoreceptor TlpB. H. pylori mutants lacking both TlpA and TlpD (ΔtlpAD) are unable to sense acid and are defective in establishing colonization in the murine stomach. However, blocking acid production in the stomach with omeprazole rescues ΔtlpAD’s colonization defect. We used 3D confocal microscopy to determine how acid blockade affects the distribution of H. pylori in the stomach. We found that stomach acid controls not only the overall bacterial density, but also the microscopic distribution of bacteria that colonize the epithelium deep in the gastric glands. In omeprazole treated animals, bacterial abundance is increased in the antral glands, and gland colonization range is extended to the corpus. Our findings indicate that H. pylori has evolved at least two independent receptors capable of detecting acid gradients, allowing not only survival in the stomach, but also controlling the interaction of the bacteria with the epithelium.

Effects of applied potential on the stress corrosion cracking behavior of 7003 aluminum alloy in acid and alkaline chloride solutions

Potentiodynamic polarization tests and slow strain rate test (SSRT) in combination with fracture morphology observations were conducted to investigate the stress corrosion cracking (SCC) behavior of 7003 aluminum alloy (AA7003) in acid and alkaline chloride solutions under various applied potentials (Ea). The results show that AA7003 is to a certain extent susceptible to SCC via anodic dissolution (AD) at open-circuit potential (OCP) and is highly susceptible to hydrogen embrittlement (HE) at high negative Ea in the solutions with pH levels of 4 and 11. The susceptibility increases with negative shift in the potential when Ea is less than −1000 mV vs. SCE. However, the susceptibility distinctly decreases because of the inhibition of AD when Ea is equal to −1000 mV vs. SCE. In addition, the SCC susceptibility of AA7003 in the acid chloride solution is higher than that in the alkaline solution at each potential. Moreover, the effect of hydrogen on SCC increases with increasing hydrogen ion concentration.

Effects of pH value on growth morphology of LaPO4 nanocrystals: investigated from experiment and theoretical calculations

The morphologies of the materials have strong effects on their performance in particular applications. In our experiment, we synthesized LaPO4 successfully by the typical hydrothermal method in acidic conditions. The morphologies, preferred orientation and crystal facets are characterized by scanning electron microscopy, selected-area electron diffraction and high-resolution transmission electron microscopy. Combining the experimental findings, the surface energies of two major surfaces, (110) and (031) planes, were calculated using density functional theory methods. The theoretical calculations on the slabs surface energies were performed to simulate the shape of nanoparticles by the Wulff construction. The experimental results indicate that LaPO4 prepared in this work shows rodlike structure. The equilibrium shape of clava with large length–diameter ratio is achieved. With increasing hydrogen ion concentration in solutions, the morphologies present as sticks and their length–diameter ratios tend bigger, which is consistent with experimental results to a great extent.

Removal of chloride from simulated zinc sulfate electrolyte by ozone oxidation

The removal of chloride from simulated zinc sulfate electrolyte by ozone oxidation was investigated. The effects of various process factors including the O2 flow, bubbling time, reaction temperature, H2SO4 and ZnSO4 concentration, and existence of Mn2+ were systematically studied. The results showed that with increasing O2 flow, the chloride removal increased first and then decreased. Increasing both the bubbling time and reaction temperature was beneficial to dechlorination while an increase in the ZnSO4 concentration had an adverse effect. With increasing sulfuric acid concentration, the dechlorination rapidly rose due to the increasing hydrogen ion concentration in electrolyte. Optimum dechlorination process conditions in the absence of Mn2+ were obtained as follows: O2 flow 0.4L·min−1, H2SO4 concentration 160g·L−1, Zn2+concentration 40g·L−1, reaction temperature 70°C, and reaction time 120min. Under these conditions, the concentration of Cl− was reduced from 300 to 5mg·L−1. The existence of Mn2+ can further accelerate the reaction of ozone with chloride, which was probably through charge-transfer and coordination catalysis mechanism.

A Fluorescent pH Chemosensor Based on Functionalized Naphthalimide in Aqueous Solution

The synthesis of functionalized naphthalimide (compound 1) and its application for the preparation of pH chemosensor was described. The fluorescence enhancement of compound 1 with the increase of hydrogen ion concentration is based on the hindering of photo-induced electron transfer (PET) from aliphatic amine group to the naphthalimide. The comparison of this method with some other fluorescence methods based on naphthalimide for the measurement of pH indicated that the method can be applied in aqueous solutions rather than organic solutions. The analytical performance characteristics of the proposed pH chemosensor were also investigated. The chemosensor can be applied to the determination of pH between 3.20 and 7.80. Common inorganic ions do not show obvious interference for pH measurements. Moreover, the response of the chemosensor for pH is fast (response time less than 3 min). In addition, the chemosensor has been used for determination of pH in urine samples with satisfactory results.

Selenium dioxide catalysed oxidation of acetic acid hydrazide by bromate in aqueous hydrochloric acid medium

Selenium dioxide catalysed acetic acid hydrazide oxidation by bromate was studied in hydrochloric acid medium. The order in oxidant concentration, substrate and catalyst were found to be unity. Increasing hydrogen ion concentration increases the rate of the reaction due to protonation equilibria of the oxidant. The mechanism of the reaction involves prior complex formation between the catalyst and substrate, hydrazide, followed by its oxidation by diprotonated bromate in a slow step. Acetic acid was found to be the oxidation product. Other kinetic data like effect of solvent polarity and ionic strength on the reaction support the proposed mechanism. Selenium dioxide catalysed acetic acid hydrazide oxidation by bromate was studied in hydrochloric acid medium. The mechanism of the reaction involves prior complex formation between the catalyst and hydrazide, followed by its oxidation by diprotonated bromate in a slow step.

Occurrence of metabolic alkalosis in rumen lactic acidosis: A review article

The pH of the extracellular fluids is one of the most vigorously regulated variables of the body. Acidosis is associated with an increase in hydrogen ion concentration (decreasing pH), whereas alkalosis is caused by a decrease in hydrogen ion concentration (increasing pH). The published literature indicates that the occurrence of metabolic alkalosis in acute rumen lactic acidosis is most probable in the early and end stages of sub-acute rumen lactic acidosis or acute cases resulting from rumen lactic acidosis.

ChemInform Abstract: Kinetics and Mechanism of Oxidation of Tin(II) by Hexachloroiridate(IV) in Aqueous Perchlorate Solutions

The kinetics of hexachloroiridate(IV) oxidation of tin(II) in aqueous perchlorate media at a constant ionic strength of 2.0 mol dm -3 have been studied spectrophotometrically. The reaction was found to follow second-order overall kinetics and first order with respect to each of the reactants. The results showed hydrogen ion dependence where the reaction rate increased with increasing hydrogen ion concentration. The activation parameters were evaluated and a tentative reaction mechanism has been discussed.

Stress Effects of Simulated Acid Rain on Photosynthetic Characteristics and Yield of Field-grown Spring Wheat at the Filling Stage in Semi Arid Rain Feed Region

In order to investigate the effect of acid rain on photosynthetic characteristics of spring wheat,spring wheat at the filling stage was sprayed with simulated acid rain at different pH level of 1.5,2.5,3.5,4.5 and 5.6,and then,the yield and the photosynthetic parameters of spring wheat leaves were monitored.The results indicated:①The net photosynthetic rate reduces in the range of 9.61% to 61.50%,stomatal conductance reduces in the range of 7.03% to 57.46%,transpiration rate reduces in the range of 3.70% to 55.44%,intercellular CO2 concentration increases in the range of 27.91% to 43.74%,the chlorophyll relative content reduces in the range of 12.12% to 41.92%,the yield of spring wheat reduces in the range of 15.50% to 37.05%.Effect of simulated acid rain on photosynthetic characteristics of spring wheat leaves increases more and more remarkable with the increase of hydrogen ion concentration.②The pH values of simulated acid rain was significantly positively correlated with net photosynthetic rate,transpiration rate,stomatal conductance,the relative chlorophyll content and the yield,and the pH values of simulated acid rain was significantly negatively correlated with intercellular CO2 concentration.

Cultural conditions required for the induction of an adaptive acid-tolerance response (ATR) in Sinorhizobium meliloti and the question as to whether or not the ATR helps rhizobia improve their symbiosis with alfalfa at low pH

Sinorhizobium meliloti associates with Medicago and Melilotus species to develop nitrogen-fixing symbioses. The agricultural relevance of these associations, the worldwide distribution of acid soils, and the remarkable acid sensitivity of the microsymbiont have all stimulated research on the responses of the symbionts to acid environments. We show here that an adaptive acid-tolerance response (ATR) can be induced in S. meliloti, as shown previously for Sinorhizobium medicae, when the bacteria are grown in batch cultures at the slightly acid pH of 6.1. In marked contrast, no increased tolerance to hydrogen ions is obtained if rhizobia are grown in a chemostat under continuous cultivation at the same pH. The adaptive ATR appears as a complex process triggered by an increased hydrogen-ion concentration, but operative only if other--as yet unknown--concomitant factors that depend on the culture conditions are present (although not provided under continuous cultivation). Although the stability of the ATR and its influence on acid tolerance has been characterized in rhizobia, no data have been available on the effect of the adapted state on symbiosis. Coinoculation experiments showed that acid-adapted indicator rhizobia (ATR+) were present in >90% of the nodules when nodulation was performed at pH 5.6, representing a >30% increase in occupancy compared with a control test. We show that the ATR represents a clear advantage in competing for nodulation at low pH. It is not yet clear whether such an effect results from an improved performance in the acid environment during preinfection, an enhanced ability to initiate infections, or both conditions. The practical use of ATR+ rhizobia will depend on validation experiments with soil microcosms and on field testing, as well as on the possibility of preserving the physiology of ATR+ bacteria in inoculant formulations.

Acid–base balance and weight gain: Are there crucial links via protein and organic acids in understanding obesity?

Obesity is associated with ever increasing social costs posing a general public health challenge. The most obvious reason for obesity, given healthy body functioning, is a positive calorie balance. This article delves into the lesser studied realm of the relationship of weight gain, in particular adipose tissue gain, with increased hydrogen ion concentration, taking protein and organic acids as important caveats in this discussion. The review opens the topic with the contradictory result of various studies reporting a positive relationship between chronic metabolic acidosis and weight loss. It goes to explain a process of weight gain, primarily adipose tissue gain, on acidogenic diets. Insufficient dietary protein could lead to muscle loss, and individual organic acids might indicate if there is any fatty acid oxidation or accumulation of hydrogen ion. The solution to the acid accumulation is discussed not in protein limitation but an increase in the consumption of vegetables and fruits. Finally, this review article based on studies published puts forward a physiological basis including a hypothesis to explain the possible link between hydrogen ion concentration and weight gain. This link could possibly explain the development of diseases and aging partially, and warrants research.

Extraction of niobium and tantalum isotopes using organophosphorus compounds. Part II – Extraction of “carrier-free” concentrations from HCl/LiCl solutions

We have studied the extraction of niobium and tantalum from mixed hydrochloric acid/lithium chloride media by bis(2-ethylhexyl) hydrogen phosphate (HDEHP) and bis(2-ethylhexyl) hydrogen phosphite (BEHP) as a function of hydrogen ion (H+) concentration. The amount of niobium extracted by both HDEHP and BEHP decreased with increasing hydrogen ion concentration. Equilibrium with niobium occurred within 10 s at all hydrogen ion concentrations for both systems. For tantalum, the amount extracted increased until 6−9 M H+, before decreasing at higher H+ concentrations when extracted by both HDEHP and BEHP. Equilibrium occurred within 10 s at two H+ concentrations when extracted by HDEHP. The data obtained are used as the basis to discuss the speciation of Nb and Ta under the conditions studied and to evaluate possible extraction mechanisms.

Lipophilic Polymer Membrane Optical Sensor with a Synthetic Receptor for Saccharide Detection

An optical sensing approach for the detection of saccharides based on reversible boronic acid-diol complexation in a lipophilic polymer membrane is presented. The complexation of saccharides with phenyl boronic acids that are immobilized in a hydrophobic polymer matrix produces a stable boronate anion and liberates a mobile hydrogen ion. The change in fluorescence intensity of the sensing films resulting from the increase in hydrogen ion concentration is thus directly related to the ambient saccharide concentration. By monitoring the pH change in a bulk optical film, we were able to detect D-glucose, D-fructose, D-galactose, and D-sorbitol with a concentration range from 0.1 to 100 mM at physiological pH 7.4.

Noninvasive determination of exercise-induced hydrodgen ion threshold through direct optical measurement

The intensity of exercise above which oxygen uptake (Vo2) does not account for all of the required energy to perform work has been associated with lactate accumulation in the blood (lactate threshold, LT) and elevated carbon dioxide output (gas exchange threshold). An increase in hydrogen ion concentration ([H+]) is approximately concurrent with elevation of blood lactate and CO2 output during exercise. Near-infrared spectra (NIRS) and invasive interstitial fluid pH (pHm) were measured in the flexor digitorum profundus during handgrip exercise to produce a mathematical model relating the two measures with an estimated error of 0.035 pH units. This NIRS pHm model was subsequently applied to spectra collected from the vastus lateralis of 10 subjects performing an incremental-intensity cycle protocol. Muscle oxygen saturation (SmO2) was also calculated from spectra. We hypothesized that a H+ threshold could be identified for these subjects and that it would be different from but correlated with the LT. Lactate, gas exchange, SmO2, and H+ thresholds were determined as a function of Vo2 using bilinear regression. LT was significantly different from both the gas exchange threshold (Delta = 0.27 +/- 0.29 l/min) and H+ threshold (Delta = 0.29 +/- 0.23 l/min), but the gas exchange threshold was not significantly different from the H+ threshold (Delta = 0.00 +/- 0.38 l/min). The H+ threshold was strongly correlated with LT (R2 = 0.95) and the gas exchange threshold (R2 = 0.85). This initial study demonstrates the feasibility of noninvasive pHm estimations, the determination of H+ threshold, and the relationship between H+ and classical metabolic thresholds during incremental exercise.

Mechanism of Oxidation of L-Cysteine by Hexachloroiridate(IV) — A Kinetic Study

The kinetics of oxidation of L-Cysteine in aqueous HClO4 medium were studied using a one-equivalent oxidant, hexachloroiridate(IV). The reaction exhibits second-order dependence with respect to hexachloroiridate(IV) and first-order in cysteine. The rate decreases with increase in hydrogen ion concentration indicating that the zwitterionic form of cysteine is more reactive. Cysteic acid is identified as the product of oxidation. A suitable mechanism involving the formation of [IrCl6]2− – sulphur bonded intermediate is proposed. The activation parameters of the reaction are computed using the linear least squares method and the values of Ea and ΔS# are found to be 27.97±1.82 kJ mol−1 and −51.30±6.0 J K−1mol−1, respectively.